warranter

Century Dictionary and Cyclopedia

1. n. One who warrants. Specifically— One who gives authority or legally empowers.

Wiktionary

1. n. One who warrants, gives authority, or legally empowers.
2. n. One who gives a warranty or guarantee.

GNU Webster's 1913

1. n. One who warrants, gives authority, or legally empowers.
2. n. (Law) One who assures, or covenants to assure; one who contracts to secure another in a right, or to make good any defect of title or quality; one who gives a warranty; a guarantor.

WordNet 3.0

1. n. one who provides a warrant or guarantee to another