| Obsolete calculator | 19 |
| Obsolete club | 13 |
| Obsolete coin | 13 |
| Obsolete communication | 22 |
| Obsolete court tactic | 21 |
| Obsolete curtain material? | 26 |
| Obsolete dashboard option | 25 |
| Obsolete disc player | 20 |
| Obsolete for "obsolete" | 33 |
| Obsolete form of "to be" | 34 |
| Obsolete geog. abbr. | 20 |
| Obsolete hypothesis about the universe's origin | 51 |
| Obsolete Italian currency units | 31 |
| Obsolete item | 13 |
| Obsolete map abbr. | 18 |
| Obsolete math aid | 17 |
| Obsolete math-class tool | 24 |
| Obsolete palindromic preposition | 32 |
| Obsolete phone part | 19 |
| Obsolete piano key material | 27 |
| Obsolete plane | 14 |
| Obsolete pocket | 15 |
| Obsolete preposition | 20 |
| Obsolete prison garb | 20 |
| Obsolete program saver, for short | 33 |
| Obsolete recording mode. abbr. | 30 |
| Obsolete recordings, for short | 30 |
| Obsolete records | 16 |
| Obsolete repro machine | 22 |
| Obsolete rulers | 15 |
| Obsolete sound system | 21 |
| Obsolete Spanish coin | 21 |
| Obsolete suffix | 15 |
| Obsolete symbol | 15 |
| Obsolete term for legal insanity | 32 |
| Obsolete typewriter accessory | 29 |
| Obsolete VCR format | 19 |
| Obsolete VCR's | 18 |
| Obsolete videotape format | 25 |
| Obstacle | 8 |
| Obstacle clearer | 16 |
| Obstacle course impediment | 26 |
| Obstacle course in some video games | 35 |
| Obstacle encountered at 12 a.m.? | 32 |
| Obstacle for a barber | 21 |
| Obstacle for a sleeping princess | 32 |
| Obstacle for an aspiring D.A. | 29 |
| Obstacle for an author | 22 |
| Obstacle for Curtis Strange | 27 |
| Obstacle for George of the Jungle | 33 |
| Obstacle for Moses | 18 |
| Obstacle for Santa? | 19 |
| Obstacle in Exodus | 18 |
| Obstacle in father-son relations | 32 |
| Obstacle in red | 15 |
| Obstacle on a car-racing track | 30 |
| Obstacle on the way to second base? | 35 |
| Obstacle race | 13 |
| Obstacle surmounted by Hannibal's army in 218 B.C. | 54 |
| Obstacle to a city planner's vision? | 40 |
| Obstacle to compromise, at times | 32 |
| Obstacle to free speech? | 24 |
| Obstacle to getting things done | 31 |
| Obstacle to progress | 20 |
| Obstacle, sometimes | 19 |
| Obstacle, to Hamlet | 19 |
| Obstacle, to Shakespeare | 24 |
| Obstacle-course items | 21 |
| Obstacle-course racing division for cats or dogs | 48 |
| Obstacles | 9 |
| Obstacles for barbers | 21 |
| Obstacles for Hannibal | 22 |
| Obstacles for marauders | 23 |
| Obstacles in Frogger | 20 |
| Obstacles on the course | 23 |
| Obstacles to quiet on the set? | 30 |
| Obstetric test, familiarly | 26 |
| Obstetric test, for short | 25 |
| Obstetrical bays? | 17 |
| Obstetrical period | 18 |
| Obstetrician Fernand | 20 |
| Obstetrician's announcement | 31 |
| Obstetrician's calculation | 30 |
| Obstetrician's determination | 32 |
| Obstetrician's estimates | 28 |
| Obstetrician's guess?: Abbr. | 32 |
| Obstetrician's job | 22 |
| Obstetrician? | 13 |
| Obstetricians' calculations | 31 |
| Obstetricians' org. | 23 |
| Obstetrics device | 17 |
| Obstetrics? | 11 |
| Obstinate | 9 |
| Obstinate animal | 16 |
| Obstinate animals | 17 |
| Obstinate beast | 15 |
| Obstinate cuss | 14 |
| Obstinate equine | 16 |
| Obstinate equines | 17 |
| Obstinate one | 13 |