The Collaborative International Dictionary of English v.0.48:

Intermittent \In`ter*mit"tent\, n. (Med.)
   An intermittent fever or disease. --Dunglison.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Intermittent \In`ter*mit"tent\, a. [L. intermittens, -entis, p.
   pr. of intermittere: cf. F. intermittent.]
   Coming and going at intervals; alternating; recurrent;
   periodic; as, an intermittent fever. --Boyle.
   [1913 Webster]

   Intermittent fever (Med.), a disease with fever which
      recurs at certain intervals; -- applied particularly to
      fever and ague. See Fever.

   Intermittent gearing (Mach.), gearing which receives, or
      produces, intermittent motion.

   Intermittent springs, springs which flow at intervals, not
      apparently dependent upon rain or drought. They probably
      owe their intermittent action to their being connected
      with natural reservoirs in hills or mountains by passages
      having the form of a siphon, the water beginning to flow
      when it has accumulated so as to fill the upper part of
      the siphon, and ceasing when, by running through it, it
      has fallen below the orifice of the upper part of the
      siphon in the reservoir.
      [1913 Webster]

WordNet (r) 3.0 (2006):

intermittent
    adj 1: stopping and starting at irregular intervals;
           "intermittent rain showers"

Moby Thesaurus II by Grady Ward, 1.0:

111 Moby Thesaurus words for "intermittent":
   alternate, alternating, arrested, beating, broken, broken off,
   capricious, careening, catchy, checked, chopped-off, choppy,
   circling, cyclic, cyclical, decousu, desultory, deviative,
   disconnected, discontinued, discontinuous, discrete, disjunctive,
   eccentric, episodic, epochal, erratic, even, every other, fitful,
   flickering, fluctuating, guttering, halting, herky-jerky,
   heteroclite, immethodical, incoherent, inconstant, infrequent,
   intermitting, interrupted, irregular, isochronal, isochronous,
   iterative, jagged, jerky, lurching, measured, metrical, metronomic,
   noncontinuous, nonlinear, nonsequential, nonserial, nonuniform,
   occasional, on-again-off-again, oscillatory, parenthetic, patchy,
   periodic, periodical, pulsating, pulsing, rambling, random,
   reciprocal, recurrent, recurring, rhythmic, rhythmical, rotary,
   rough, scrappy, seasonal, serial, snatchy, spasmatic, spasmic,
   spasmodic, spastic, sporadic, spotty, staggering, steady,
   suspended, uncertain, unconnected, undulant, undulatory, unequal,
   uneven, unjoined, unmethodical, unmetrical, unregular,
   unrhythmical, unsettled, unsteady, unsuccessive, unsystematic,
   variable, veering, wandering, wavelike, wavering, wheeling,
   wobbling, wobbly