"act of taking food," Old English feding, verbal noun from feed (v.). Feeding frenzy is from 1989, metaphoric extension of a phrase that had been used of sharks since 1950s.
late 13c., demaunde, "a question," from Old French demande, from demander "to request; to demand" (see demand (v.)). Meaning "a request, a claim, an asking for by virtue of a right or supposed right to the thing sought," also "that which is demanded or required, exaction as a tribute or concession," without reference to right, is from c. 1300.
In the political economy sense of "desire to purchase and possess, coupled with the means to do so" (correlating to supply) it is attested from 1776 in Adam Smith. Meaning "state of being sought after" (especially by consumers) is from 1711. In demand "much sought after" is attested by 1825; on demand "on being requested" is from 1690s.
late 14c., demaunden, "ask questions, make inquiry," from Old French demander (12c.) "to request; to demand," from Latin demandare "entrust, charge with a commission" (in Medieval Latin, "to ask, request, demand"), from de- "completely" (see de-) + mandare "to order" (see mandate (n.)).
Meaning "ask for with insistence or urgency" is from early 15c., from Anglo-French legal use ("to ask for as a right"). Meaning "require as necessary or useful" is by 1748. Related: Demanded; demanding.
1530s, "to demand, to claim," from Latin expostulatus, past participle of expostulare "to demand urgently, remonstrate, find fault, dispute, complain of, demand the reason (for someone's conduct)," from ex "from" (see ex-) + postulare "to demand" (see postulate (v.)). Friendlier sense of "to reason earnestly (with someone) against a course of action, etc." is first recorded in English 1570s. Related: Expostulated; expostulating.
1580s, "action of remonstrating in a friendly manner;" 1590s, "argumentative protest," from Latin expostulationem (nominative expostulatio) "a pressing demand, complaint," noun of action from past-participle stem of expostulare "demand urgently," from ex "from" (see ex-) + postulare "to demand" (see postulate (v.)).