heron (n.)

"long-necked, long-legged wading bird," c. 1300, from Old French hairon, eron (12c.), earlier hairo (11c., Modern French héron), from Frankish *haigiro or some other Germanic source, from Proto-Germanic *hraigran. Related to Old High German heigaro, Danish hejre "heron," German Reiher, Dutch reiger, Old Norse hegri), perhaps from a common IE root imitative of its cry (compare Old Church Slavonic kriku "cry, scream," Lithuanian krykšti "to shriek," Welsh cregyra "heron," Latin graculus "jackdaw, crow"). Old English cognate hraga did not survive into Middle English. Egret is from the same source.

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Definitions of heron from WordNet
heron (n.)
grey or white wading bird with long neck and long legs and (usually) long bill;
Heron (n.)
Greek mathematician and inventor who devised a way to determine the area of a triangle and who described various mechanical devices (first century);
Synonyms: Hero / Hero of Alexandria