Unicellular :  adj : having or consisting of a single cell

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