bounteous adj.

late 13c., "a gift, a reward, a favor bestowed freely;" c. 1300, "goodness, virtue; beauty; ; excellence; knightly prowess, strength, valor, chivalry," early 14c., "a helpful act, an act of generosity, a good deed," also "liberality in giving, generosity, munificence," from Anglo-French bountee, Old French bonte "goodness" (12c., Modern French bonté), from Latin bonitatem (nominative bonitas) "goodness," from bonus "good" (see bonus).

The sense of "gift bestowed by a sovereign or the state" led to the extended senses of "premium or gratuity to a military recruit" (1702) and "reward for killing or taking a criminal or enemy" (1764) or dangerous animal (1847).

Bounty-jumper "one who enlists in the military, collects the bounty, and flees without reporting for duty" is from the American Civil War (by 1864). Bounty-hunter is from 1893, American English, originally in reference to wild animals.

I do ... promise, that there shall be paid ... the following several and respective premiums and Bounties for the prisoners and Scalps of the Enemy Indians that shall be taken or killed .... ["Papers of the Governor of Pennsylvania," 1764]

word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."

mid-15c., "liberal in bestowing gifts;" see bounty + -ful. From 1530s as "characterized by bounty, abundant, ample." Related: Bountifully; bountifulness.