perk v.

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.

["Susannah," Scottish alliterative poem, c. 1390]

"horizontal bar serving as a support for various purposes," late 14c., "rod, pole, perch for a hawk," a variant of perch (n.1) or from Medieval Latin perca, Old French perce, variant of perche.

1869, a shortened, colloquial form of perquisite (q.v.), also perq. As a verb, 1934 as a shortened and altered form of percolate, also perc.