<p><strong>Noun</strong></p><ul><li>An affix placed before a word, base, or another prefix to modify a term's meaning, as by making the term negative, as un- in unkind, by signaling repetition, as re- in reinvent, or by indicating support, as pro- in proabolition.</li><li>Compatible prefixes can work together, as un- and re- in unrefundable.</li><li>Something prefixed, as a title before a person's name: She uses the prefix “Ms.” rather than "Mrs."</li></ul><p><strong>Verb</strong></p><ul><li>(Used with object) To fix or put before or in front: to prefix an impressive title to one's name.</li><li>To add as a prefix.</li><li>To fix, settle, or determine beforehand: If you call a taxi, the rate to the airport will be prefixed.</li><li>(Biology) To apply the first of two fixatives to.</li></ul>