/ Dictionary / Index O On Liberty*: Meaning and Definition of Find definitions for: On" Lib'erty Pronunciation: [key] a treatise (1859) by John Stuart Mill on the rights of the individual within the state. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. onlay onliest Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language