The Collaborative International Dictionary of English v.0.48:

Loop \Loop\, n. [Cf. Ir. & Gael. lub loop, noose, fold, thong,
   bend, lub to bend, incline.]
   1. A fold or doubling of a thread, cord, rope, etc., through
      which another thread, cord, etc., can be passed, or which
      a hook can be hooked into; an eye, as of metal; a staple;
      a noose; a bight.
      [1913 Webster]

            That the probation bear no hinge, nor loop
            To hang a doubt on.                   --Shak.
      [1913 Webster]

   2. A small, narrow opening; a loophole.
      [1913 Webster]

            And stop all sight-holes, every loop from whence
            The eye of Reason may pry in upon us. --Shak.
      [1913 Webster]

   3. A curve of any kind in the form of a loop.
      [1913 Webster]

   4. (Telegraphy) A wire forming part of a main circuit and
      returning to the point from which it starts.
      [1913 Webster]

   5. (Acoustics) The portion of a vibrating string, air column,
      etc., between two nodes; -- called also ventral segment.
      [1913 Webster]

   Loop knot, a single knot tied in a doubled cord, etc. so as
      to leave a loop beyond the knot. See Illust. of Knot.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Loop \Loop\ (l[=oo]p), n. [G. luppe an iron lump. Cf.
   Looping.] (Iron Works)
   A mass of iron in a pasty condition gathered into a ball for
   the tilt hammer or rolls. [Written also loup.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Loop \Loop\ (l[=oo]p), v. t. [imp. & p. p. Looped (l[=oo]pt);
   p. pr. & vb. n. Looping.]
   To make a loop of or in; to fasten with a loop or loops; --
   often with up; as, to loop a string; to loop up a curtain.
   [1913 Webster]

WordNet (r) 3.0 (2006):

loop
    n 1: fastener consisting of a metal ring for lining a small hole
         to permit the attachment of cords or lines [syn: cringle,
         eyelet, loop, grommet, grummet]
    2: anything with a round or oval shape (formed by a curve that
       is closed and does not intersect itself)
    3: (computer science) a single execution of a set of
       instructions that are to be repeated; "the solution took
       hundreds of iterations" [syn: iteration, loop]
    4: an inner circle of advisors (especially under President
       Reagan); "he's no longer in the loop"
    5: the basic pattern of the human fingerprint
    6: a computer program that performs a series of instructions
       repeatedly until some specified condition is satisfied
    7: the topology of a network whose components are serially
       connected in such a way that the last component is connected
       to the first component [syn: loop topology, loop]
    8: an intrauterine device in the shape of a loop
    9: a complete electrical circuit around which current flows or a
       signal circulates [syn: closed circuit, loop] [ant: open
       circuit]
    10: a flight maneuver; aircraft flies a complete circle in the
        vertical plane [syn: loop, loop-the-loop]
    v 1: move in loops; "The bicycle looped around the tree"
    2: make a loop in; "loop a rope" [syn: loop, intertwine]
    3: fly loops, perform a loop; "the stunt pilot looped his plane"
    4: wind around something in coils or loops [syn: coil, loop,
       curl] [ant: uncoil]
    5: fasten or join with a loop; "He looped the watch through his
       belt"

Moby Thesaurus II by Grady Ward, 1.0:

255 Moby Thesaurus words for "loop":
   O, air hole, ambit, annular muscle, annulus, arc, arch, areola,
   armhole, association, aureole, band, bank, beat, begird, belt,
   belt in, bend, bend back, beset, bilge, blain, bleb, blister, blob,
   blowhole, boss, bow, braid, break, broken circuit, bubble, bulb,
   bulge, bulla, bullet-hole, bump, bunch, bunghole, burl, button,
   cahot, chaplet, chine, cincture, circle, circlet, circuit,
   circuital field, circumference, circus, closed circle,
   closed circuit, clump, coil, compass, complete circuit, condyle,
   conference, convex, corona, coronet, crab, cringle, crook, crown,
   curl, curve, cycle, dead circuit, deadeye, decurve, deflect,
   diadem, dip, discus, disk, dome, dowel, ear, embow, encincture,
   encircle, encompass, engird, enlace, ensphere, entwine,
   eternal return, eye, eyelet, fairy ring, feather, fishtail, flange,
   flap, flex, full circle, gall, galvanic circuit, garland, gasket,
   gird, girdle, glory, gnarl, grommet, ground loop, guide, halo,
   handle, hill, hook, hoop, hot circuit, hump, hunch, incurvate,
   incurve, inflect, interknit, interlace, intertie, intertissue,
   intertwine, intertwist, interweave, intort, jog, joggle, keyhole,
   knit, knob, knot, knothole, knur, knurl, lace, lap, lasso,
   lateral circuit, leg, lip, live circuit, logical circle, loom,
   loophole, looplet, lump, magic circle, magnetic circuit, manhole,
   mat, microcircuit, mole, mountain, mousehole, multiple circuit,
   multiple series, net, nevus, noose, nub, nubbin, nubble, orbit,
   papilloma, path, peephole, peg, pigeonhole, pinhole, placket,
   placket hole, plait, pleach, plow, porpoise, porthole,
   printed circuit, pull out, pull up, punch-hole, push down, raddle,
   radius, recurve, reflect, reflex, retroflex, revolution, rib,
   ridge, ring, roll, rondelle, round, round trip, roundel, rounds,
   sag, saucer, series multiple, short, short circuit, shoulder,
   sideslip, skid, sphincter, spin, spine, spiracle, spiral, splice,
   staple, stud, stunt, style, swag, sweep, tab, tap, tie, tissue,
   tour, tubercle, tubercule, turn, twill, twine, twine around, twist,
   undulate, vault, vector field, vent, venthole, verruca, vesicle,
   vicious circle, wale, walk, wart, wattle, weave, web, welt, wheel,
   whorl, wind, wreath, wreathe, wreathe around, yaw, zone



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

loop
loop through

    A sequence of instructions in a program that
   the processor repeats, either until some condition is met, or
   indefinitely (an infinite loop).

   In an structured language (e.g. C, Pascal, BASIC, or
   Fortran), a loop is usually achieved with for loop, while
   loop or repeat loop constructs.

   In other languages these constructs may be synthesised with a
   jump (assembly language) or a GOTO (early Fortran or
   BASIC).

   To "loop through" a list means to process each element in turn.
   Hackers might use this for everyday iterative actions, e.g.  "I've
   got to loop through my paper mail."

   (2014-12-20)


Easton's 1897 Bible Dictionary:

Loop
   a knotted "eye" of cord, corresponding to the "taches" or knobs
   in the edges of the curtains of the tabernacle, for joining them
   into a continuous circuit, fifty to a curtain (Ex. 26:4, 5, 10,
   11).