employer

n. boss, person who employs people to do work

Noun
1. a person or firm that employs workers
(antonym) employee
(hypernym) leader
(hyponym) boss, hirer
(derivation) hire, engage, employ

v. use; employ, exercise, harness; bestow

(n.)
One who employs another; as, an employer of workmen.
  

Any person engaged in a business affecting interstate commerce who owns or leases a commercial motor vehicle in connection with that business, or assigns employees to operate it, but such terms does not include the United States, any State, any political subdivision of a State, or an agency established under a compact between States approved by the Congress of the United States. (49CFR390)