noun

• (by extension) Any species of Cetacea.
  "The dawn of the oil age was fairly recent. Although the stuff was used to waterproof boats in the Middle East 6,000 years ago, extracting it in earnest began only in 1859 after an oil strike in Pennsylvania.[…]It was used to make kerosene, the main fuel for artificial lighting after overfishing led to a shortage of whale blubber."
• (figuratively) Something, or someone, that is very large.
  "It was a whale of a job. […] It took two months, and the fair blush of youth off my cheeks."
• (figuratively, as "whale of a ___") Something, or someone, that is excellent.
  "My own father only wrote one poem in his life as far as I know, but it was a whale of a lyric, the kind you would give your whole life to write, which he did, but that is another story."
• (gambling, figuratively) A gambler who routinely wagers large amounts of money.
  "These are often no-limit games as maximum bets cramp a whale’s style."

verb

• (intransitive) To hunt for whales.

verb

• (slang, transitive) To thrash, to flog, to beat vigorously or soundly.
  "Brought him back, put him in the stall—low stable—got out of his reach, and then begun to whale him. Then he kicked up agin; […]"