| Underwater transmission | 23 |
| Underwater sound device | 23 |
| Underwater sound detectors | 26 |
| Underwater search vessel | 24 |
| Underwater search device | 24 |
| Underwater salvager, e.g. | 25 |
| Underwater research vessel | 26 |
| Underwater research site | 24 |
| Underwater power source? | 24 |
| Underwater pit residents | 24 |
| Underwater object locater | 25 |
| Underwater naval habitat | 24 |
| Underwater military guy | 23 |
| Underwater lateral surface? | 27 |
| Underwater ink stains? | 22 |
| Underwater ink squirter | 23 |
| Underwater hazard marker | 24 |
| Underwater forest plant | 23 |
| Underwater fishing aid | 22 |
| Underwater experiment site | 26 |
| Underwater excavation machine | 29 |
| Underwater escape mechanism | 27 |
| Underwater entertainment? | 25 |
| Underwater electricity source | 29 |
| Underwater detection systems | 28 |
| Underwater detection system | 27 |
| Underwater detection device | 27 |
| Underwater current generator | 28 |
| Underwater craft, briefly | 25 |
| Underwater concrete depositor | 29 |
| Underwater cave dweller | 23 |
| Underwater breathing organs | 27 |
| Underwater breathing gear | 25 |
| Underwater breathing aids | 25 |
| Underwater breathing aid | 24 |
| Underwater bloodsucker | 22 |
| Underwater army dangers? | 24 |
| Undertaking, in Britain | 23 |
| Undertakes without permission | 29 |
| Undertaker's purchase | 25 |
| Undertake precipitately | 23 |
| Undertake legal recourse | 24 |
| Undertake halfheartedly | 23 |
| Understudy's study | 22 |
| Understudy's dream | 22 |
| Understudy's crime? | 23 |
| Understood, as a punch line | 27 |
| Understood what one did wrong | 29 |
| Understood one did wrong | 24 |
| Understood by very few | 22 |
| Understood by only a few | 24 |
| Understood by a select few | 26 |
| Understood archeology? | 22 |
| Understood archaeology? | 23 |
| Understatement for effect | 25 |
| Understands, to a Scot | 22 |
| Understands, as sheet music | 27 |
| Understands, as a joke | 22 |
| Understands the problem | 23 |
| Understands the point of | 24 |
| Understands the operation | 25 |
| Understands the matter | 22 |
| Understands on a deep level | 27 |
| Understanding, of sorts | 23 |
| Understanding utterance | 23 |
| Understanding responses | 23 |
| Understanding response | 22 |
| Understanding of a sort | 23 |
| Understanding comments | 22 |
| Understanding between nations | 29 |
| Understand, to Kerouac | 22 |
| Understand, to hipsters | 23 |
| Understand, instinctually | 25 |
| Understand, informally | 22 |
| Understand, in sci-fi lingo | 27 |
| Understand, in sci-fi jargon | 28 |
| Understand, in hippie lingo | 27 |
| Understand, as a language | 25 |
| Understand without hearing | 26 |
| Understand what's implied | 29 |
| Understand the true nature of | 29 |
| Understand the difference | 25 |
| Understand President Bush | 25 |
| Understand or be punished | 25 |
| Understand intuitively | 22 |
| Understand incorrectly | 22 |
| Understaffed situation | 22 |
| Undersized stock trade | 22 |
| Undersized pickpocket? | 22 |
| Undersized flower girl? | 23 |
| Undersides of overhangs | 23 |
| Underside-of-the-desk gunk | 26 |
| Underside of some shoes | 23 |
| Undershirt, in Britain | 22 |
| Undersea prowler, briefly | 25 |
| Undersea party pooper? | 22 |
| Undersea explorer Jacques | 25 |
| Undersea craft (Abbr.) | 22 |
| Underpinnings of Windows 1.0 | 28 |
| Underpay a comic actor? | 23 |