| radiant |
emitting heat or rays of light. [3 definitions] |
| radiant energy |
energy transmitted by waves, such as electromagnetic radiation or heat. |
| radiant flux |
the rate at which radiant energy such as heat or light flows through a given area. |
| radiate |
to send forth rays or waves, as of heat or electromagnetic radiation. [8 definitions] |
| radiation |
the emission of particles or waves of energy, as by radioactive material or by electrical circuits or devices. [3 definitions] |
| radiationless |
combined form of radiation. |
| radiation sickness |
sickness induced by overexposure to ionizing radiation such as x-rays or gamma rays, resulting in nausea, diarrhea, bleeding, hair loss, sterility, and often death. |
| radiator |
a device, such as that in a car, consisting of tubes through which fluid coolant passes. [3 definitions] |
| radical |
of or relating to roots, origins, or fundamental characteristics; basic. [6 definitions] |
| radicalism |
the advocacy of radical political or social changes. [2 definitions] |
| radicalize |
to make or become radical, esp. in political or social ideas. |
| radical sign |
a mathematical sign placed before a quantity to indicate extraction of its root. |
| radicand |
in mathematics, the number, variable, or quantity under a radical sign. |
| radicchio |
a variety of chicory with slightly bitter, purplish red leaves that are used in salads. |
| radicle |
the lower part of a plant embryo or seedling, esp. the beginnings of a root. |
| radii |
a plural form of radius. |
| radio |
the sending of communications by means of electromagnetic waves in the frequency range from ten kilocycles to three hundred thousand megacycles. [9 definitions] |
| radio- |
radio. [3 definitions] |
| radioactive |
emitting energy or subatomic particles as a result of the decay of unstable isotopes. [2 definitions] |
| radioactive dating |
any of several methods of determining the age of an artifact, rock, or bone based on the known rate of decay of radioactive isotopes. |
| radioactivity |
the emission or amount of emission of energy or subatomic particles by the nuclei of certain unstable isotopes of elements as they decay. |