The Collaborative International Dictionary of English v.0.48:

Ebb tide \Ebb" tide`\
   The reflux of tide water; the retiring tide; -- opposed to
   flood tide.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "ebb tide":
   dead low water, direct tide, ebb, ebb and flow, flood, flood tide,
   flow, flux, flux and reflux, full tide, high tide, high water,
   low tide, low water, lunar tide, neap, neap tide, opposite tide,
   refluence, reflux, rip, riptide, solar tide, spring tide,
   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