Lemma \Lem"ma\ (l[e^]m"m[.a]), n.; pl. L. {Lemmata} (-m[.a]*t[.a]), E. {Lemmas} (-m[.a]z). [L. lemma, Gr. lh^mma anything received, an assumption or premise taken for granted, fr. lamba`nein to take, assume. Cf. {Syllable}.] A preliminary or auxiliary proposition demonstrated or accepted for immediate use in the demonstration of some other proposition, as in mathematics or logic.