Old English fedan "nourish, feed, sustain, foster," from Proto-Germanic *fodjan (cf. Old Saxon fodjan, Old Frisian feda, Dutch voeden, Old High German fuotan, Old Norse foeða, Gothic fodjan "to feed"), from PIE *pa- "to protect, feed" (see food). Feeding frenzy is from 1989, metaphoric extension of a phrase that had been used of sharks since 1950s.
"action of feeding," 1570s, from feed (v.). Meaning "food for animals" is first attested 1580s. Of machinery, from 1892.
Not feeling or looking well; indisposed
[1862+; used of animals by 1816]