Booty
late Middle English (originally denoting plunder acquired in common): from Middle Low German būte, buite ‘exchange, distribution’, of uncertain origin.
wiktionary
From Middle English buty, botye, bottyne, from Old French butin, botin, from Middle Low German bǖte(“distribution, exchange, loot”), of obscure origin, but related to Middle High German biute, German Beute(“booty”). Possibly ultimately from Gaulish *boudi, from Proto-Celtic *boudi(“profit, gains; victory”).
Probably an alteration of botty. Possibly influenced by booty (etymology 1).
From boot.
etymonline
booty (n.)
mid-15c., bottyne "plunder taken from an enemy in war," from Old French butin "booty" (14c.), from a Germanic source akin to Middle Low German bute "exchange." Influenced in form and sense (toward "profit, gain," whether taken by force or not) by boot (n.2) and in form by nouns ending in -y. Meaning "female body considered as a sex object" is 1920s, African-American vernacular. As with other male sexual terms for women, its sense can shift to copulation generally or to the eroticized body parts (compare nookie, ass, etc.).