Prefix

A prefix is an affix which is placed before the root of a word. Particularly in the study of languages, a prefix is also called a preformative, because it alters the form of the words to which it is affixed. For an example:

  • unhappy : un is a negative or antonymic prefix.
  • prefix, preview : pre is a prefix, with the sense of before
  • redo, review. : re is a prefix meaning again.

The word prefix is itself made up of the stem fix (meaning attach, in this case), and the prefix pre- (meaning "before"), both of which are derived from Latin roots.