The Collaborative International Dictionary of English v.0.48:
Sweetener \Sweet"en*er\, n. One who, or that which, sweetens; one who palliates; that which moderates acrimony. [1913 Webster]WordNet (r) 3.0 (2006):
sweetener n 1: something added to foods to make them taste sweeter [syn: sweetening, sweetener] 2: anything that serves as an enticement [syn: bait, come- on, hook, lure, sweetener]