perk (v.) Look up perk at
late 14c., "to make oneself trim or smart," perhaps from Old North French perquer "to perch" (Modern French percher; see perch (n.1)), on notion of a bird preening its plumage. Sense of "raise oneself briskly" is first attested 1520s; perk up "recover liveliness" is from 1650s. Related: Perked; perking.
perk (n.) Look up perk at
1869, shortened colloquial form of perquisite (q.v.), also perq. As a verb, 1934 as shortened and altered form of percolate, also perc.