Other forms: morphemes
In linguistics, the smallest unit of language or grammar is called a morpheme. You can break words down into morphemes — like the -s at the end of a noun that tells you it's plural or the -ly at the end of a word that shows it's an adverb.
While some words can be divided into two or more morphemes, others consist of a single morpheme. The word dog, for example, is considered a "free" morpheme, because it can stand alone. Prefixes and suffixes like un- and -ing, are "bound" morphemes, dependent for meaning on other morphemes. A linguist coined the word in 1895, modeling it after phoneme, "distinct unit of sound," and adding the Greek morphe, "form or shape."