whale (n.) Look up whale at Dictionary.com
Old English hwæl, from Proto-Germanic *khwalaz (cf. Old Saxon hwal, Old Norse hvalr, hvalfiskr, Swedish val, Middle Dutch wal, walvisc, Dutch walvis, Old High German wal, German Wal); probably cognate with Latin squalus "a kind of large sea fish." Phrase whale of a "excellent or large example" is c.1900, student slang.
whale (v.) Look up whale at Dictionary.com
"beat, whip severely," 1790, possibly a variant of wale (v.).