Synonym Words List Starting With O
| obey | mind, heed, comply |
| oblivious | unconscious, preoccupied, dazed |
| obnoxious | offensive, abominable, repulsive |
| observe | examine, study, scrutinize |
| obsolete | extinct, dated, antiquated |
| obstinate | stubborn, bullheaded, adamant |
| odd | peculiar, weird, strange |
| offend | displease, affront, disgust |
| ominous | threatening, menacing |
| opaque | obscure, murky, unclear |
| open | begin, unfold, originate |
| opponent | enemy, rival, foe |
| optimistic | hopeful, confident |
| optional | voluntary, elective |
| ordinary | usual, average |
| outrageous | preposterous, shocking |
| outstanding | extraordinary, distinguished |
