| Triatomic 1. (a.) Having three atoms; -- said of certain elements or radicals. 2. (a.) Having a valence of three; trivalent; sometimes, in a specific sense, having three hydroxyl groups, whether acid or basic; thus, glycerin, glyceric acid, and tartronic acid are each triatomic. Thesaurus Entries a certain, an, any, any one, atomatic, atomiferous, atomistic, corpuscular, cyclic, diatomic, dibasic, either, embryonic, evanescent, exclusive, germinal, granular, heteroatomic, heterocyclic, hexatomic, homocyclic, impalpable, imperceptible, imponderable, inappreciable, indiscernible, individual, indivisible, infinitesimal, intangible, integral, invisible, irreducible, isobaric, isocyclic, isoteric, isotopic, lone, microcosmic, microscopic, molecular, monadic, monatomic, monistic, one, pentatomic, simple, single, singular, sole, solid, solitary, subatomic, tenuous, tetratomic, thin, triatomic, tribasic, ultramicroscopic, unanalyzable, undivided, uniform, unique, unitary, unseeable, whole |