A morpheme is the smallest meaning -bearing unit of language.
Kangaroo is one morpheme. Kangaroos is two morphemes, kangaroo and plural -s. The -s expresses the meaning 'many' or 'more than one' in this example.
Morpheme may also be used for 'grammatical morpheme', see morpheme (i.e. grammatical morpheme).
- moneme (Martinet)
The term morpheme was coined by Jan Baudouin de Courtenay in c. 1880. It is based on Greek morph- 'form' and the suffix -eme, on the analogy of the term phoneme. See Mugdan (1986) for detailed discussion.
Mugdan, Joachim. 1986. Was ist eigentlich ein Morphem?