| 1. | existing or occurring under water. |
| 2. | designed to be used under water. |
| 3. | located below a ship's waterline. |
| 4. | beneath the water: to travel underwater. |
| 5. | the water beneath the surface: cold currents in the underwater. |
| 6. | underwaters, the depths, as of a sea, lake, etc. |
underwater