noun.
One, such as a person or corporation, that makes or gives a promise, assurance, or pledge typically relating to quality, durability, or performance.
noun.
One who makes or gives a guaranty.
The Century Dictionary and Cyclopedia
noun.
One who makes a guaranty.
the GNU version of the Collaborative International Dictionary of English
noun.
One who makes or gives a guaranty; a warrantor; a surety.
noun.
One who engages to secure another in any right or possession.