| Operaman portrayer on "Weekend Update" | 48 |
| Operatic heroine wooed by Beckmesser | 36 |
| Operatic partner of "Pag" | 35 |
| Operatic singer and actress Alberghetti | 39 |
| Operatic spear carrier, for short | 33 |
| Operatic toast of two continents | 32 |
| Operating system between Puma and Panther | 41 |
| Operating system designed by AT&T employees | 47 |
| Operating system developed at Bell Labs | 39 |
| Operating system developed by AT&T originally | 49 |
| Operating system on many Internet servers | 41 |
| Operating system since the '60s | 35 |
| Operating system that doesn't do Windows? | 45 |
| Operating system whose code names are confections | 49 |
| Operating without ___ (taking risks) | 36 |
| Operation Crossroads event, 1946 | 32 |
| Operation Deliberate Force nation | 33 |
| Operation Desert Storm's beginning | 38 |
| Operation Dragoon's loc.: Abbr. | 35 |
| Operation for a new liver or kidney | 35 |
| Operation in "The Sting" | 34 |
| Operation in a medical thriller, for short | 42 |
| Operation Just Cause's setting | 34 |
| Operation Overlord vessel, for short | 36 |
| Operation that often precedes an entrapment claim | 49 |
| Operation __ Freedom (2003-2011 conflict) | 41 |
| Operation ____: naval Antarctica project | 40 |
| Operations were once commonly performed in this | 47 |
| Operator of the MilleMiglia program | 35 |
| Operator of the original N.Y.C. subway | 38 |
| Operator's courteous request | 32 |
| Operators are involved with them | 32 |
| Operetta character whose son is Nanki-Poo | 41 |
| Opeth "Watershed" opener | 34 |
| Ophelia's flower "for thoughts" | 45 |
| Ophthalmic conditions known medically as hordeola | 49 |
| Ophthalmologist's application | 33 |
| Ophthalmologist's diagnosis? | 32 |
| Ophthalmologist's easy diagnosis | 36 |
| Ophthalmologist's favorite film (1981) | 42 |
| Ophthalmologist's prescription | 34 |
| Ophthalmologist's solution, maybe | 37 |
| Opiate often used in cough syrup | 32 |
| Opinion opposed to established views | 36 |
| Opinion piece published at the start of the year? | 49 |
| Opinion protected by the right of free speech | 45 |
| Opp. of ''prescription'' | 40 |
| Oppenheimer's creation, colloquially | 40 |
| Opponent of Deep Blue, IBM's chess computer | 47 |
| Opponent of management, at times | 32 |
| Opponent of Tom and Harry in 1948 | 33 |
| Opponents of defense lawyers: Abbr. | 35 |
| Opponents of the '60s-'70s New Left | 43 |
| Opponents' separator in some sports | 39 |
| Opportunities to run away from home | 35 |
| Opportunity for a football squad | 32 |
| Opportunity for a Hollywood hopeful | 35 |
| Opportunity for a radio talk show caller | 40 |
| Opportunity for a singer or comedian | 36 |
| Opportunity for an exchange of opinions | 39 |
| Opportunity for cheek-to-cheek dancing | 38 |
| Opportunity for public discussion | 33 |
| Opportunity to examine some headwear? | 37 |
| Opportunity to get off some shots | 33 |
| Opportunity to go beyond the first grade? | 41 |
| Opportunity to make amends, maybe | 33 |
| Opportunity's fellow Mars rover | 35 |
| Opposed to dividing one's apartment? | 40 |
| Opposed to, in "Li'l Abner" | 41 |
| Opposer of background checks: Abbr. | 35 |
| Opposing team's confrontation | 33 |
| Opposite direction of a Hitchcock classic? | 42 |
| Opposite leg divided by the hypotenuse | 38 |
| Opposite of ''avant'' | 37 |
| Opposite of ''blanc'' | 37 |
| Opposite of ''free'' | 36 |
| Opposite of ''guerre'' | 38 |
| Opposite of ''matin'' | 37 |
| Opposite of ''noir'' | 36 |
| Opposite of ''paleo'' | 37 |
| Opposite of ''pobre'' | 37 |
| Opposite of ''vive'' | 36 |
| Opposite of ''whoa!'' (Var.) | 44 |
| Opposite of ''yippee!'' | 39 |
| Opposite of 'sustain,' in a courtroom | 45 |
| Opposite of "'neath" | 34 |
| Opposite of "'tis" | 32 |
| Opposite of "All rise" | 32 |
| Opposite of "At ease!" | 32 |
| Opposite of "at the bottom of" | 40 |
| Opposite of "Attention!" | 34 |
| Opposite of "Ã bas" | 32 |
| Opposite of "back east" | 33 |
| Opposite of "brighten" | 32 |
| Opposite of "catalysts" | 33 |
| Opposite of "celebrate" | 33 |
| Opposite of "Count me out!" | 37 |
| Opposite of "Dep." on a flight board | 46 |
| Opposite of "dissipate" | 33 |
| Opposite of "dissuaded from" | 38 |