Etymology
Advertisement

radiation (n.)

mid-15c., radiacion, "act or process of emitting light," from Latin radiationem (nominative radiatio) "a shining, radiation," noun of action from past-participle stem of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius).

Meaning "rays or beams emitted" is from 1560s. Meaning "divergence from a center" is 1650s. In modern physics, "emission or transmission of energy in the form of waves or particles," especially in reference to ionizing radiation, from early 20c.

Others are reading

Advertisement
Advertisement
Definitions of radiation

radiation (n.)
energy that is radiated or transmitted in the form of rays or waves or particles;
radiation (n.)
the act of spreading outward from a central source;
radiation (n.)
syndrome resulting from exposure to ionizing radiation (e.g., exposure to radioactive chemicals or to nuclear explosions); low doses cause diarrhea and nausea and vomiting and sometimes loss of hair; greater exposure can cause sterility and cataracts and some forms of cancer and other diseases; severe exposure can cause death within hours;
he was suffering from radiation
Synonyms: radiation sickness / radiation syndrome
radiation (n.)
the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay;
Synonyms: radioactivity
radiation (n.)
the spread of a group of organisms into new habitats;
radiation (n.)
a radial arrangement of nerve fibers connecting different parts of the brain;
radiation (n.)
(medicine) the treatment of disease (especially cancer) by exposure to a radioactive substance;
Synonyms: radiotherapy / radiation therapy / actinotherapy / irradiation
From wordnet.princeton.edu