/ Dictionary / Index O obs.: Meaning and Definition of Find definitions for: obs. Pronunciation: [key] observation. observatory. obsolete. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: obs (Thesaurus) obrogation obscene Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language