| Tetratomic 1. (a.) Consisting of four atoms; having four atoms in the molecule, as phosphorus and arsenic. 2. (a.) Having a valence of four; quadrivalent; tetravalent; sometimes, in a specific sense, having four hydroxyl groups, whether acid or basic. 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 |