/ Dictionary / Index U Upper Carboniferous: Meaning and Definition of Find definitions for: Up'per Carbonif'erous Pronunciation: [key] — Geol. Geol. Pennsylvanian (defs. 2, 4). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Upper Canadian upper case Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language