word stem

In linguistics, a stem is the part of a word that is common to all its inflected variants. Stems are often roots, i.e. atomic (unanalyzable)  lexical morphemes, but a stem can also be morphologically complex, as seen with compound words (cf. the compound nouns meat ball or bottle opener) or words with derivational morphemes (cf. the derived verbs black-en or standard-ize). Thus, the stem of the complex English noun [photo-graph]-er] is photographer and its only other inflected form is the plural photographers.
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