Webster’s Revised Unabridged Dictionary · 1913 Guarantor Guar′an·tor′ (găr′ăn·tôr′), n. [See Guaranty, and cf. Warrantor.] (Law) (a) One who makes or gives a guaranty; a warrantor; a surety. (b) One who engages to secure another in any right or possession. ‹ Guarantee Guaranty ›