n. [ Gr. &unr_;, neut. &unr_;, p. pr. of &unr_; to go up; &unr_; up + &unr_; to go. ] (Chem.) An electro-negative atom or group of atoms, or the element which, in electro-chemical decompositions, is evolved at the anode; -- opposed to cation. Faraday. [ 1913 Webster ]

adj. 1. having the character of an anion; negatively charged; containing anions; -- of atoms, molecules, and groups of atoms. Contrasted with cationic. [ PJC ]

2. of or pertaining to anions. Contrasted with cationic [ WordNet 1.5 ]

n. 1. a class of synthetic detergents in which the molecules do not ionize in aqueous solutions.
Syn. -- anionic detergent, non-ionic detergent [ WordNet 1.5 ]