Webster’s Revised Unabridged Dictionary · 1913
Lemma
Lem′ma (lĕm′mȧ), n.; pl. L. Lemmata (-mȧ·tȧ), E. Lemmas (-mȧz). [L. lemma, Gr. λῆμμα anything received, an assumption or premise taken for granted, fr. λαμβάνειν 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.