Webster's Revised Unabridged Dictionary · 1913

Perk

Perk (pẽrk) , transitive verb

[Compare Welsh percu to trim, to make smart.]

To make trim or smart; to straighten up; to erect; to make a jaunty or saucy display of; as, to perk the ears; to perk up one's head. — Cowper
Collocations (1)
to perk up one's ears , to begin to listen attentively; -- usually used when something of interest is mentioned in some discourse, after one's attention had lapsed; as, he perked up his ears when he heard his name mentioned.

Perk , intransitive verb

1.
To exalt one's self; to bear one's self loftily.
To perk over them. — Barrow
2.
To act in a jaunty or presumptuous manner.
Collocations (1)
To perk it , to carry one's self proudly or saucily. — Pope

Perk , adjective

Smart; trim; spruce; jaunty; vain.
Perk as a peacock. — Spenser

Perk , intransitive verb

To peer; to look inquisitively. — Dickens

perk , noun

A perquisite. [informal]