"compensation claimed by the deserted party at the separation of an unmarried couple cohabiting," 1979, coined from pal (n.) + alimony. Popularized, if not introduced, during lawsuit against U.S. film star Lee Marvin (1924-1987).
"partner, mate, chum," slang, 1680s, said to be from Romany (English Gypsy) pal "brother, comrade," a variant of continental Romany pral, plal, phral, which are probably from Sanskrit bhrata "brother" (from PIE root *bhrater- "brother"). Colloquial extended form palsy-walsy is attested from 1930. Pally (adj.) is attested by 1895.
1650s, "nourishment," also "allowance to a wife from a husband's estate, or in certain cases of separation," from Latin alimonia "food, support, nourishment, sustenance," from alere "to nourish, rear, support, maintain" (from PIE root *al- (2) "to grow, nourish") + -monia suffix signifying action, state, condition (cognate with Greek -men). Derived form palimony coined 1979, from pal (n.). Related: Alimonious.
<a href="https://www.etymonline.com/word/palimony">Etymology of palimony by etymonline</a>
Harper, D. (n.d.). Etymology of palimony. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/palimony