Source : Webster's Revised Unabridged Dictionary (1913)

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

   {Neap tides}, the lowest tides of the lunar month, which
      occur in the second and fourth quarters of the moon; --
      opposed to {spring tides}.