Polyatomic
Pronunciation : Pol`y*a*tom"ic
Part of Speech : a.
Etymology : [Poly- + atomic.] (Chem.) (a) Having more than one atom in the molecule; consisting of several atoms. (b) Having a valence greater than one. [Obs.]
Source : Webster's Unabridged Dictionary, 1913
Merriam-Webster's Everyday Language Reference Set: Includes: The Merriam-Webster Dictionary, The Merriam-Webster Thesaurus, and The Merriam-Webster Vocabulary Builder