Source : Webster's Revised Unabridged Dictionary (1913)

Eagre \Ea"gre\, n. [AS. e['a]gor, ?gor, in comp., water, sea,
   e['a]gor-stre['a]m water stream, sea.]
   A wave, or two or three successive waves, of great height and
   violence, at flood tide moving up an estuary or river; --
   commonly called the bore. See {Bore}.

Source : WordNet®

eagre
     n : a high wave (often dangerous) caused by tidal flow (as by
         colliding tidal currents or in a narrow estuary) [syn: {tidal
         bore}, {bore}, {aegir}, {eager}]