(a.) Having a valence of one; capable of combining with, or of being substituted for, one atom of hydrogen; monovalent; -- said of certain atoms and radicals.

monadal monadic one-sided uniangulate unibivalent unibranchiate unicameral unicellular unicuspid unidentate unidigitate unidimensional unidirectional uniflorous unifoliate unifoliolate unigenital uniglobular unilateral unilinear uniliteral unilobed unilobular unimodular unimolecular uniocular unipart unipartite unipolar univalent univocal