The Collaborative International Dictionary of English v.0.48:

Neap \Neap\, n.
   A neap tide.
   [1913 Webster]

         High springs and dead neaps.             --Harkwill.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Neap \Neap\, n. [Cf. Neb, Nape.]
   The tongue or pole of a cart or other vehicle drawn by two
   animals. [U.S.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Neap \Neap\ (n[=e]p), a. [As. n[=e]pfl[=o]d neap flood; cf.
   hnipian to bend, incline.]
   Low.
   [1913 Webster]

   Neap tides, the lowest tides of the lunar month, which
      occur in the second and fourth quarters of the moon; --
      opposed to spring tides.
      [1913 Webster]

WordNet (r) 3.0 (2006):

neap
    n 1: a less than average tide occurring at the first and third
         quarters of the moon [syn: neap tide, neap] [ant:
         springtide]

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "neap":
   couchant, crouched, dead low water, debased, depressed,
   direct tide, ebb, ebb and flow, ebb tide, flat, flood, flood tide,
   flow, flux, flux and reflux, full tide, high tide, high water,
   knee-high, knocked flat, laid low, low, low tide, low water,
   low-built, low-hung, low-level, low-leveled, low-lying, low-set,
   low-statured, lunar tide, neap tide, opposite tide, prone,
   recumbent, refluence, reflux, rip, riptide, runty, short,
   solar tide, spring tide, squat, squatty, stooped, stumpy, supine,
   thalassometer, tidal amplitude, tidal current, tidal current chart,
   tidal flow, tidal range, tide, tide chart, tide gate, tide gauge,
   tide race, tide rip, tidewater, tideway, unelevated