[ verb ih-rey-dee-eyt; adjective ih-rey-dee-it, -eyt ]
/ verb ɪˈreɪ diˌeɪt; adjective ɪˈreɪ di ɪt, -ˌeɪt /

verb (used with object), ir·ra·di·at·ed, ir·ra·di·at·ing.

verb (used without object), ir·ra·di·at·ed, ir·ra·di·at·ing.

  1. to emit rays; shine.
  2. to become radiant.


irradiated; bright.


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Origin of irradiate

1595–1605; < Latin irradiātus, past participle of irradiāre to shine upon. See ir-1, radiate

OTHER WORDS FROM irradiate Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for irradiator

/ (ɪˈreɪdɪˌeɪt) /


(tr) physics to subject to or treat with light or other electromagnetic radiation or with beams of particles
(tr) to expose (food) to electromagnetic radiation to kill bacteria and retard deterioration
(tr) to make clear or bright intellectually or spiritually; illumine
a less common word for radiate (def. 1)
(intr) obsolete to become radiant

Derived forms of irradiate

irradiative, adjectiveirradiator, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for irradiator

[ ĭ-rādē-āt′ ]


To expose to radiation, as for diagnostic or therapeutic purposes.
To treat with radiation.
To apply radiation to a structure or organism.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for irradiator

[ ĭ-rādē-āt′ ]

To expose to or treat with radiation. For example, meat sold as food is often irradiated with x-rays or other radiation to kill bacteria; uranium 238 can be irradiated with neutrons to create fissionable plutonium 239.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.