Irradiation

How to spell irradiation

11 letters · 5 syllables

How to pronounce irradiation

Say the part in capitals loudest.

What does irradiation mean?

1. nounThe process of exposing something or someone to radiation such as light, X-rays, or gamma rays.

Irradiation in a sentence

• The factory uses irradiation to kill bacteria in packaged spices.

• Doctors warned the patient about the side effects of repeated irradiation during cancer treatment.

Where does irradiation come from?

Language of origin: Latin

This word traces back to the Latin verb irradiare, meaning 'to shine upon' or 'to cast rays into', which was built from the prefix in- (here meaning 'into' and assimilated to ir- before the letter r) and radiare 'to emit beams', itself from radius, the Latin word for a ray or beam of light (and also a rod or the spoke of a wheel). The Latin noun irradiatio described the act of shining light onto something. English adopted the term in the early 1600s, at first in the literal sense of flooding something with light, before science broadened it to cover exposure to any kind of radiation, including X-rays, ultraviolet light, and the controlled treatment of food or tissue. The same radius root gives us 'radiant', 'radiate', and even 'radio'. The spelling trap lives at the very start: the prefix in- has assimilated into a doubled r, so writers must remember the two r's in 'irr-' before the single d.

How the word is built

• ir- (in, into; variant of in- before r)
• radi (from Latin radius: ray, beam)
• -ation (noun of action)