from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The amount of ionizing radiation required to produce the same biological effect as one rad of high-penetration x-rays.
- n. A unit for measuring absorbed doses of radiation, equivalent to one roentgen of x-rays or gamma rays.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Acronym rapid eye movement, a sleep state.
- n. A dose of absorbed radiation equivalent to one roentgen of X-rays or gamma rays
- n. A remark; a programming language statement used for documentation (in BASIC for example); also used in DOS batch files.
- abbr. remaining
r(oentgen) e(quivalent in) m(an).(American Heritage® Dictionary of the English Language, Fourth Edition)
Abbreviation of Roentgen equivalent in man. (Wiktionary)