morpheme that is attached to a word stem to form a new word

An affix is a piece added to a word, or root,[1] which signals or changes its role in a sentence. It is part of grammar.[2]p18 Affixes may occur in various positions in a word:

  • Prefix: before the word/root, for instance: anti-climax; re-write.
  • Suffix: after the word/root, for instance: climactic; walked. Most plurals.
  • Infix: Inside the word/root. Rare in English, example: the m in recumbent.
  • Interfix: between words, to connect them: the reduced and in sun 'n sand; editor-in-chief.


  1. Root = the part of a word which does not change.
  2. McArthur, Tom (ed) 1992. The Oxford companion to the English language. Oxford University Press.