| Operatic vocal solo | 19 |
| Operatic voice | 14 |
| Operatic voices | 15 |
| Operating | 9 |
| Operating alone | 15 |
| Operating at a loss | 19 |
| Operating at a profit | 21 |
| Operating at capacity | 21 |
| Operating at maximum | 20 |
| Operating at peak capacity | 26 |
| Operating automatically | 23 |
| Operating conditions | 20 |
| Operating expense? | 18 |
| Operating expenses | 18 |
| Operating handle | 16 |
| Operating in either of two ways | 31 |
| Operating periods | 17 |
| OPERATING PHYSICIAN HAS TROUBLE WITH STATIC CLING! | 50 |
| Operating procedures (abbr.) | 28 |
| Operating procedures: Abbr. | 27 |
| Operating profitably | 20 |
| Operating room | 14 |
| Operating room aide | 19 |
| Operating room apparel | 22 |
| Operating room assistant | 24 |
| Operating room covers | 21 |
| Operating room devices | 22 |
| Operating room helper | 21 |
| Operating room insert | 21 |
| Operating room item | 19 |
| Operating room necessities | 26 |
| Operating room number? | 22 |
| Operating room request | 22 |
| Operating room substance, once | 30 |
| Operating room? | 15 |
| Operating simultaneously | 24 |
| Operating space | 15 |
| Operating system | 16 |
| Operating system before Windows | 31 |
| Operating system between Puma and Panther | 41 |
| Operating system choice | 23 |
| 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 for PCs | 24 |
| Operating system on many Internet servers | 41 |
| Operating system option | 23 |
| Operating system since 1969 | 27 |
| Operating system since the '60s | 35 |
| Operating system that doesn't do Windows? | 45 |
| Operating system whose code names are confections | 49 |
| Operating system, abbr. | 23 |
| Operating with efficiency | 25 |
| Operating with ulterior motives | 31 |
| Operating without ___ | 21 |
| Operating without ___ (taking risks) | 36 |
| Operating without _____ | 23 |
| Operating, as radar | 19 |
| Operating-room process | 22 |
| Operation | 9 |
| Operation "souvenir" | 30 |
| Operation aftermath | 19 |
| Operation aids | 14 |
| Operation Allied Force gp. | 26 |
| Operation at the Alamo | 22 |
| Operation attire | 16 |
| Operation by an obstetrician | 28 |
| Operation centers? | 18 |
| Operation creation | 18 |
| Operation Crossroads event, 1946 | 32 |
| Operation Cyclone org. | 22 |
| Operation Deliberate Force nation | 33 |
| Operation Desert Fox, e.g. | 26 |
| Operation Desert Storm | 22 |
| Operation Desert Storm setting | 30 |
| Operation Desert Storm target | 29 |
| Operation Desert Storm's beginning | 38 |
| Operation Dragoon's loc.: Abbr. | 35 |
| Operation Enduring Care gp. | 27 |
| Operation Enduring Care sponsor | 31 |
| Operation Exodus participant | 28 |
| Operation for a new liver or kidney | 35 |
| Operation for Bugs? | 19 |
| Operation Hastings org. | 23 |
| Operation IceBridge grp. | 24 |
| Operation in "The Sting" | 34 |
| Operation in 1998 news | 22 |
| Operation in a medical thriller, for short | 42 |
| Operation Just Cause target | 27 |
| Operation Just Cause's setting | 34 |
| Operation locations, for short | 30 |
| Operation Mail Call gp. | 23 |
| Operation Mail Call grp. | 24 |
| Operation memento | 17 |
| Operation Neptune Spear org. | 28 |
| Operation Overlord beach | 24 |
| Operation Overlord high point | 29 |
| Operation Overlord launch | 25 |
| Operation Overlord monogram | 27 |
| Operation Overlord overseer | 27 |