Definition & Meaning of "morpheme"

What is a "morpheme"?

A morpheme is the smallest meaningful unit of language that contributes to the meaning of a word. Morphemes can be classified into two main types: free morphemes, which can stand alone as words, such as "book" or "run", and bound morphemes, which cannot stand alone and must be attached to a base word, such as prefixes or suffixes like "un-" in "unhappy" or "-ed" in "walked". Morphemes play a crucial role in word formation and grammar, as they help convey specific meanings and grammatical functions, allowing for the construction of complex words and expressions in a language.