late 14c., perken, "to make oneself trim or smart," perhaps literally "to perch on a tree," from Old North French perquer "to perch" (Modern French percher; see perch (n.1), and compare perk (n.1)), on notion of a bird preening its plumage. Sense of "raise briskly, hold up smartly" is attested from 1520s; perk up "recover liveliness" is from 1650s. Related: Perked; perking.
Þe popeiayes perken and pruynen for proude On peren and pynappel.
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy).