The Collaborative International Dictionary of English v.0.48:

Cycle \Cy"cle\ (s?"k'l), n. [F. ycle, LL. cyclus, fr. Gr.
   ky`klos ring or circle, cycle; akin to Skr. cakra wheel,
   circle. See Wheel.]
   1. An imaginary circle or orbit in the heavens; one of the
      celestial spheres. --Milton.
      [1913 Webster]

   2. An interval of time in which a certain succession of
      events or phenomena is completed, and then returns again
      and again, uniformly and continually in the same order; a
      periodical space of time marked by the recurrence of
      something peculiar; as, the cycle of the seasons, or of
      the year.
      [1913 Webster]

            Wages . . . bear a full proportion . . . to the
            medium of provision during the last bad cycle of
            twenty years.                         --Burke.
      [1913 Webster]

   3. An age; a long period of time.
      [1913 Webster]

            Better fifty years of Europe than a cycle of Cathay.
                                                  --Tennyson.
      [1913 Webster]

   4. An orderly list for a given time; a calendar. [Obs.]
      [1913 Webster]

            We . . . present our gardeners with a complete cycle
            of what is requisite to be done throughout every
            month of the year.                    --Evelyn.
      [1913 Webster]

   5. The circle of subjects connected with the exploits of the
      hero or heroes of some particular period which have served
      as a popular theme for poetry, as the legend of Arthur and
      the knights of the Round Table, and that of Charlemagne
      and his paladins.
      [1913 Webster]

   6. (Bot.) One entire round in a circle or a spire; as, a
      cycle or set of leaves. --Gray.
      [1913 Webster]

   7. A bicycle or tricycle, or other light velocipede.
      [1913 Webster]

   8. A motorcycle.
      [PJC]

   9. (Thermodynamics) A series of operations in which heat is
      imparted to (or taken away from) a working substance which
      by its expansion gives up a part of its internal energy in
      the form of mechanical work (or being compressed increases
      its internal energy) and is again brought back to its
      original state.
      [Webster 1913 Suppl.]

   10. (Technology) A complete positive and negative, or forward
       and reverse, action of any periodic process, such as a
       vibration, an electric field oscillation, or a current
       alternation; one period. Hence: (Elec.) A complete
       positive and negative wave of an alternating current. The
       number of cycles (per second) is a measure of the
       frequency of an alternating current.
       [Webster 1913 Suppl. + PJC]

   Calippic cycle, a period of 76 years, or four Metonic
      cycles; -- so called from Calippus, who proposed it as an
      improvement on the Metonic cycle.

   Cycle of eclipses, a period of about 6,586 days, the time
      of revolution of the moon's node; -- called Saros by the
      Chaldeans.

   Cycle of indiction, a period of 15 years, employed in Roman
      and ecclesiastical chronology, not founded on any
      astronomical period, but having reference to certain
      judicial acts which took place at stated epochs under the
      Greek emperors.

   Cycle of the moon, or Metonic cycle, a period of 19
      years, after the lapse of which the new and full moon
      returns to the same day of the year; -- so called from
      Meton, who first proposed it.

   Cycle of the sun, Solar cycle, a period of 28 years, at
      the end of which time the days of the month return to the
      same days of the week. The dominical or Sunday letter
      follows the same order; hence the solar cycle is also
      called the cycle of the Sunday letter. In the Gregorian
      calendar the solar cycle is in general interrupted at the
      end of the century.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cycle \Cy"cle\ (s?"k'l), v. i. [imp. & p. p. Cycled. (-k'ld);
   p. pr. & vb. n. Cycling (-kl?ng).]
   1. To pass through a cycle[2] of changes; to recur in cycles.
      --Tennyson. --Darwin.
      [1913 Webster]

   2. To ride a bicycle, tricycle, or other form of cycle.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

cycle \cy"cle\ (s?"k'l), v. t.
   To cause to pass through a cycle[2].
   [PJC] Cyclic

WordNet (r) 3.0 (2006):

cycle
    n 1: an interval during which a recurring sequence of events
         occurs; "the never-ending cycle of the seasons" [syn:
         cycle, rhythm, round]
    2: a series of poems or songs on the same theme; "Schubert's
       song cycles"
    3: a periodically repeated sequence of events; "a cycle of
       reprisal and retaliation"
    4: the unit of frequency; one hertz has a periodic interval of
       one second [syn: hertz, Hz, cycle per second,
       cycles/second, cps, cycle]
    5: a single complete execution of a periodically repeated
       phenomenon; "a year constitutes a cycle of the seasons" [syn:
       cycle, oscillation]
    6: a wheeled vehicle that has two wheels and is moved by foot
       pedals [syn: bicycle, bike, wheel, cycle]
    v 1: cause to go through a recurring sequence; "cycle the
         laundry in this washing program"
    2: pass through a cycle; "This machine automatically cycles"
    3: ride a motorcycle [syn: motorbike, motorcycle, cycle]
    4: ride a bicycle [syn: bicycle, cycle, bike, pedal,
       wheel]
    5: recur in repeating sequences

Moby Thesaurus II by Grady Ward, 1.0:

291 Moby Thesaurus words for "cycle":
   AC, AF, CPS, DC, EHF, HF, Hz, Indian file, Kekule formula, MF, O,
   Platonic year, RF, SHF, UHF, VHF, VLF, absorption current,
   active current, aeon, age, alternate, alternating current, ambit,
   annular muscle, annulus, annus magnus, areola, array, arsis,
   articulation, atomic cluster, audio frequency, aureole, bank,
   be here again, beat, benzene ring, bicycle, bicycle-built-for-two,
   bike, bout, branched chain, bus, buzz, carrier frequency,
   catch a train, catena, catenation, chain, chain reaction, chaining,
   chaplet, chauffeur, chopper, circle, circuit, circuiteer,
   circulate, circumambulate, circumference, circummigrate,
   circumnavigate, circumvent, circus, close the circle, closed chain,
   closed circle, come again, come and go, come around,
   come full circle, come round, come round again, come up again,
   compass, compound radical, concatenation, conduction current,
   connection, consecution, continuum, convection current, corona,
   coronet, course, crown, cycle of indiction, cycles, date, day,
   delta current, descent, describe a circle, diadem, diastole,
   dielectric displacement current, direct current, discus, disk,
   displacement current, downbeat, drive, drone, eddy current,
   electric current, electric stream, emission current, encircle,
   encompass, endless belt, endless round, entrain, eternal return,
   exciting current, extremely high frequency, fairy ring, file,
   filiation, flank, free alternating current, frequency,
   frequency spectrum, full circle, galvanic current, gamut, garland,
   generation, girdle, girdle the globe, glory, go about, go around,
   go by rail, go round, go the round, gradation, great year, gyre,
   halo, hertz, heterocycle, high frequency, high-frequency current,
   homocycle, hum, idle current, indiction, induced current,
   induction current, intermediate frequency, intermit,
   ionization current, iron, joyride, juice, kilocycles, kilohertz,
   lap, lasso, lattice, line, lineage, logical circle, loop, looplet,
   low frequency, low-frequency current, lower frequencies,
   magic circle, magnetizing current, make a circuit, make a train,
   medium frequency, megacycles, megahertz, minibike, molecule,
   monocycle, monotone, motocycle, motor, motorbike, motorcycle,
   multiphase current, nexus, noose, orbit, oscillate, pattern, pedal,
   pedicab, pendulum, periodicity, pig, plenum, powder train,
   progression, pulsate, pulsating direct current, pulse, queue,
   radical, radio frequency, radius, range, rank, reactive current,
   reappear, recur, recurrence, recycle, reoccur, repeat,
   reticulation, return, revolution, revolve, ride, ring, road-bike,
   roll around, rondelle, rotary current, rotate, rotation, round,
   round trip, roundel, rounds, routine, row, run, saucer, scale,
   scooter, sequel, sequence, series, side chain, sidewalk bike,
   simple radical, single file, single-phase alternating current,
   skirt, space-lattice, spark frequency, spectrum, spell, sphincter,
   spiral, straight chain, stray current, string, succession,
   superhigh frequency, surround, swath, systole, take a joyride,
   tandem, taxi, thermionic current, thermoelectric current, thesis,
   thread, three-phase alternating current, tier, time, tour,
   trail bike, train, tricycle, trike, turn, two-wheeler,
   ultrahigh frequency, undulate, upbeat, upper frequencies,
   velocipede, very high frequency, very low frequency,
   vicious circle, voltaic current, walk, watt current, wheel,
   wheel around, windrow, wreath



The Jargon File (version 4.4.7, 29 Dec 2003):

cycle


    1. n. The basic unit of computation. What every hacker wants more of (noted
    hacker Bill Gosper described himself as a ?cycle junkie?). One can describe
    an instruction as taking so many clock cycles. Often the computer can
    access its memory once on every clock cycle, and so one speaks also of
    memory cycles. These are technical meanings of cycle. The jargon meaning
    comes from the observation that there are only so many cycles per second,
    and when you are sharing a computer the cycles get divided up among the
    users. The more cycles the computer spends working on your program rather
    than someone else's, the faster your program will run. That's why every
    hacker wants more cycles: so he can spend less time waiting for the
    computer to respond.

    2. By extension, a notional unit of human thought power, emphasizing that
    lots of things compete for the typical hacker's think time. ?I refused to
    get involved with the Rubik's Cube back when it was big. Knew I'd burn too
    many cycles on it if I let myself.?

    3. vt. Syn. bounce (sense 4), from the phrase ?cycle power?. ?Cycle the
    machine again, that serial port's still hung.?


The Free On-line Dictionary of Computing (30 December 2018):

cycle

    A basic unit of computation, one period of a computer
   clock.

   Each instruction takes a number of clock cycles.  Often the
   computer can access its memory once on every clock cycle, and
   so one speaks also of "memory cycles".

   Every hacker wants more cycles (noted hacker Bill Gosper
   describes himself as a "cycle junkie").  There are only so
   many cycles per second, and when you are sharing a computer
   the cycles get divided up among the users.  The more cycles
   the computer spends working on your program rather than
   someone else's, the faster your program will run.  That's why
   every hacker wants more cycles: so he can spend less time
   waiting for the computer to respond.

   The use of the term "cycle" for a computer clock period can
   probably be traced back to the rotation of a generator
   generating alternating current though computers generally use
   a clock signal which is more like a square wave.
   Interestingly, the earliest mechanical calculators,
   e.g. Babbage's Difference Engine, really did have parts
   which rotated in true cycles.

   [Jargon File]

   (1997-09-30)