In linguistics, a word is the smallest element that can be pronounced in isolation with objective or practical meaning.

A word may consist of a single morpheme, or several, whereas a morpheme may not be able to stand on its own as a word. A complex word will typically include a root and one or more affixes (rock-s, red-ness, quick-ly, run-ning, un-expect-ed), or more than one root in a compound (black-board, sand-box). Words can be put together to build larger elements of language, such as phrases (a red rock, put up with), clauses (I threw a rock), and sentences (He threw a rock too, but he missed).

The term word may refer to a spoken word or to a written word, or sometimes to the abstract concept behind either. Spoken words are made up of units of sound called phonemes, and written words of symbols called graphemes, such as the letters of the English alphabet.