late 14c., "to make oneself trim or smart," perhaps from O.N.Fr. perquer "to perch" (Fr. percher; see perch (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.
1869, shortened and altered form of perquisite (q.v.); 1934 as shortened and altered form of percolate (see percolation).