| Noun | 1. | REM - a recurring sleep state during which dreaming occurs; a state of Rapid Eye Movements during sleep |
| 2. | REM - (Roentgen Equivalent Man) the dosage of ionizing radiation that will cause the same amount of injury to human tissue as 1 roentgen of X-rays |
| (programming) | REM - (From "remark") The keyword used in BASIC to introduce a comment (which continues to the end of the line). MS-DOS probably borrowed it from BASIC. Might be used in the form "REM out" meaning to comment out. |