Jump To:

• rem
  rem

  noun

  the quantity of ionizing radiation whose biological effect is equal to that produced by one roentgen of x-rays.
• REM
  REM

  noun

  rapid eye movement.

rem

¹ American  

[rem] / rɛm /

noun

Nucleonics.

1. the quantity of ionizing radiation whose biological effect is equal to that produced by one roentgen of x-rays.

---

REM ² American  

[rem] / rɛm /

noun

1. rapid eye movement.

---

REM ¹ British  

abbreviation

1. rapid eye movement

---

REM ² British  

/ rɛm /

acronym

1. roentgen equivalent man

---

rem Scientific  

/ rĕm /

1. The amount of ionizing radiation required to produce the same biological effect as one rad of high-penetration x-rays. The rem has been replaced in most scientific contexts by the sievert.

---

rem Cultural  

1. An acronym for r oentgen e quivalent m an. A unit of absorbed doses of radiation.

---

Discover More

A normal medical x-ray delivers about 0.02 rem; a fatal dose of radiation is several thousand rem.

Etymology

Origin of rem¹

1945–50; r(oentgen) e(quivalent in) m(an)

Origin of REM²

First recorded in 1955–60

---

Example Sentences

See Examples For:

rem REM

The legal limit for radiation exposure in the workplace is 5 rem per year.

From Slate ● Dec. 11, 2015

Multiply by 100 to obtain dose in rem.

From Textbooks ● Aug. 12, 2015

I wouldn’t dream of doing something as stupid as leaving my home and ruining my life by becoming a refugee for 5 rem per year, let alone 2 rem.

From Forbes ● May 19, 2013

According to the government report, with each scan, the average passenger receives a dose of about 1.46 microrems, or millionths of a rem, the standard measure of a person’s radiation exposure.

From Time ● Mar. 3, 2012

Being of his flesh born they had his name Foreth rem ir Osborth, and were reared in that Clanhearth.

From "The Left Hand of Darkness" by Ursula K. Le Guin

They also needed to avoid assuming that the observed eye movements and muscle twitches necessarily represented the same processes seen during human REM sleep.

From Science Daily ● Oct. 27, 2026

A different pattern appeared as the brain moved from non-REM sleep into REM sleep.

From Science Daily ● Sep. 26, 2026

This northeast Georgia city has a rich music history, tied to bands including Widespread Panic, REM and The B-52s.

From MarketWatch ● Sep. 24, 2026

I scan to see how much deep sleep and REM I clocked.

From The Wall Street Journal ● Sep. 11, 2026

My mother is the only individual I know who can fall asleep instantly for two minutes—deep REM sleep, complete with snoring—only to be awakened instantly by certain select noises.

From "The Color of Water: A Black Man's Tribute to His White Mother" by James McBride

Random Word

Spin the wheel and learn a new word!

---