Merriam-Webster's Collegiate® Dictionary, 11th Edition
PERK
I. verb
Etymology: Middle English
Date: 14th century
intransitive verb
1. to thrust up the head, stretch out the neck, or carry the body in a bold or insolent manner, to stick up or out jauntily, to gain in vigor or cheerfulness especially after a period of weakness or depression, transitive verb to make smart or spruce in appearance ; freshen , improve , to thrust up quickly or impudently,
II. intransitive verb
Date: 1656
percolate ,
III. noun
Date: 1824
perquisite