/ Dictionary / Index P pneumatolysis: Meaning and Definition of Find definitions for: pneu•ma•tol•y•sis Pronunciation: (n"mu-tol'u-sis, ny"-), [key] — n. Geol. the process by which rocks are altered or minerals and ores are formed by the action of vapors given off by magma. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pneumatology pneumatometer Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language