REM

n.
The rapid, periodic, jerky movement of the eyes during certain stages of the sleep cycle when dreaming takes place.

[R(APID) E(YE) M(OVEMENT).]

n
roentgen-equivalent-man

A unit of absorbed radiation dose adjusted for biologic effects equivalent to 1 rad of 250 kV x-rays (dental and cephalometric x-rays require less than 100 kV).

On drawings, abbr. for “removable.”

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Initialism for "rapid eye movement," a physical phenomenon during which the most active, visually rich, and bizarre dreaming occurs.

Rapid eye movement. See also sleep.

rem