Meaning of pejoration

pej•o•ra•tion

Pronunciation: (pej"u-rā'shun, pē"ju-), [key]
— n.
  1. depreciation; a lessening in worth, quality, etc.
  2. semantic change in a word to a lower, less approved, or less respectable meaning. Cf.(def. 1).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.