Pronunciation: (met"u-sō'mu-tiz"um), [key]
1. the series of metamorphic processes whereby chemical changes occur in minerals or rocks as a result of the introduction of material, often in hot aqueous solutions, from external sources.
2. replacement (def. 4). Also,met•a•so•ma•to•sis
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.