morpheme \mor"pheme\ (m[^o]r"f[=e]m), n. (Linguistics) The smallest unit of meaning of a language, which cannot be divided into smaller parts carrying meaning; it is usually smaller than a single wordform, such as the -ed morpheme of verbs in the past tense or the -s morpheme of nouns in the plural form. [PJC]

Source: The Collaborative International Dictionary of English v.0.48
 

50 Moby Thesaurus words for "morpheme": IC analysis, accidence, affix, affixation, allomorph, bound morpheme, conjugation, cutting, declension, derivation, difference of form, enclitic, form, formative, free form, glosseme, icon, immediate constituent analysis, infix, infixation, inflection, lexeme, lexical form, morph, morphemic analysis, morphemics, morphology, morphophonemics, paradigm, phrase, prefix, prefixation, proclitic, radical, root, semasiological unit, sememe, sign, signifiant, significant, stem, suffix, suffixation, symbol, term, theme, token, type, word, word-formation

Source: Moby Thesaurus II by Grady Ward, 1.0
 

morpheme

Source: WordNet (r) 2.0