thanksgiving n.

mid-13c., plural of thank (n.), from Old English þanc, þonc in its secondary sense "grateful thought, gratitude," from Proto-Germanic *thanka-, from the same root as thank (v.). In prehistoric times the Germanic noun seems to have expanded from "a thinking of, a remembering" to also mean "remember fondly, think of with gratitude." Compare Old Saxon thank, Old Frisian thank, Old Norse þökk, Dutch dank, German Dank. The Old English noun chiefly meant "thought, reflection, sentiment; mind, will, purpose," also "grace, mercy, pardon; pleasure, satisfaction."

As short for I give you thanks from 1580s; often with extensions, such as thanks a lot (1908). Spelling thanx attested by 1907.

Old English giefan (West Saxon) "to give, bestow, deliver to another; allot, grant; commit, devote, entrust," V strong verb (past tense geaf, past participle giefen), from Proto-Germanic *geban (source also of Old Frisian jeva, Middle Dutch gheven, Dutch geven, Old High German geban, German geben, Gothic giban), from PIE root *ghabh- "to give or receive." It became yiven in Middle English, but changed to guttural "g" by influence of Old Norse gefa "to give," Old Danish givæ.

Meaning "to yield to pressure" is from 1570s. Give in "yield" is from 1610s; give out is mid-14c. as "publish, announce;" meaning "run out, break down" is from 1520s. Give up "surrender, resign, quit" is mid-12c. To give (someone) a cold seems to reflect the old belief that one could be cured of disease by deliberately infecting others. What gives? "what is happening?" is attested from 1940. To not give a (some thing regarded as trivial and valueless) is from c. 1300 (early examples were a straw, a grass, a mite).