Old English fox "a fox," from Proto-Germanic *fuhsaz "fox" (cognates Old Saxon vohs, Middle Dutch and Dutch vos, Old High German fuhs, German Fuchs, Old Norse foa, Gothic fauho), from Proto-Germanic *fuh-, from PIE *puk- "tail" (source also of Sanskrit puccha- "tail").
The bushy tail also inspired words for "fox" in Welsh (llwynog, from llwyn "bush"); Spanish (raposa, from rabo "tail"); and Lithuanian (uodegis, from uodega "tail"). Metaphoric extension to "clever person" was in late Old English. Meaning "sexually attractive woman" is from 1940s; but foxy in this sense is recorded from 1895. A fox-tail was anciently one of the badges of a fool (late 14c.).
A late Old English translation of the Medicina de Quadrupedibus of Sextus Placitus advises, for women "who suffer troubles in their inward places, work for them into a salve a foxes limbs and his grease, with old oil and with tar; apply to the womens places; quickly it healeth the troubles." It also recommends, for sexual intercourse without irritation, "the extremest end of a foxes tail hung upon the arm." Rubbing a fox's testicles on warts was supposed a means to get rid of them.
modification of Old English huntung "a hunt, chase; what is hunted, game," verbal noun from hunt (v.). Bartlett (1848) notes it as the word commonly used by sportsmen in the Southern states of the U.S. where in the North they use gunning. Happy hunting-grounds "Native American afterlife paradise" is from "Last of the Mohicans" (1826); hunting-ground in a Native American context is from 1777.