<p><strong>Noun</strong></p><ul><li>The act of making or becoming unlike.</li><li>Phonetics: The process by which a speech sound becomes different from or less like a neighboring sound, as in "pilgrim" from Latin "peregrīnus," and "purple" from Old English "purpure," or disappears entirely because of a like sound in another syllable, as in the pronunciation of "governor."</li><li>Compare assimilation.</li><li>Biology: Catabolism.</li></ul>