| radian; radians. |
| rad 3 abbr. radian |
ra·di·an (rā'dē-ən) n. Abbr. rad A unit of angular measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle, approximately 57°17'44.6". See Table at measurement. [radi(us) + -an1.] |
rad
[ræd]
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rad 1 (rād)
n.
A unit of energy absorbed from ionizing radiation, equal to 100 ergs per gram or 0.01 joule per kilogram of irradiated material.
rad 2
abbr.
radian
radian ra·di·an (rā'dē-ən)
n.
Abbr. rad
A unit of angular measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.
| rad (rād) Pronunciation Key
A unit used to measure energy absorbed by a material from radiation. One rad is equal to 100 ergs per gram of material. Many scientists now measure this energy in grays rather than in rads. |
| radian (rā'dē-ən) Pronunciation Key
A supplementary unit of the International System used in angular measure. One radian is equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle, approximately 57°17'44.6". |
RAD programming
Rapid Application Development.
rad
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| RAD Royal Academy of Dancing |
rad
the unit of absorbed dose of ionizing radiation, defined in 1962 by the International Commission on Radiological Units and Measurements as equal to the amount of radiation that releases an energy of 100 ergs per gram of matter. One rad is equal approximately to the absorbed dose delivered when soft tissue is exposed to one roentgen of medium-voltage radiation. "Rad" is derived from "radiation absorbed dose." In 1975 it was replaced by the gray (Gy), equal to 100 rads, in the International System of Units (SI). The rad is used now only in the United States.
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