/ Dictionary / Index R rock oil: Meaning and Definition of Find definitions for: rock' oil" Pronunciation: [key] petroleum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Rock of Gibraltar rockoon Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language