• synonyms


See more synonyms for rad on Thesaurus.com
  1. Informal. radical.
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  1. Slang. fine; wonderful.
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Origin of rad2

by shortening of radical
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for radder

Historical Examples

  • I ast seberal colored men, but dey'd radder whitewash an' clean chicken coops.

    Tom Swift and his Motor-cycle

    Victor Appleton

  • I'd radder take dis mutt into Fairview dan pull down a t'ousan' in de long green.

  • I'd radder go to hell on my knees backward dan tech de fust drap ob dat.

  • Beoples might radder haf deir landts for nuttin', dan bay rents for dem.

British Dictionary definitions for radder


  1. a former unit of absorbed ionizing radiation dose equivalent to an energy absorption per unit mass of 0.01 joule per kilogram of irradiated material. 1 rad is equivalent to 0.01 gray
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Word Origin

C20: shortened from radiation


symbol for
  1. radian
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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

Word Origin and History for radder


"x-ray dose unit," 1918, shortened form of radiation (q.v.). As shortened form of radical (n.), it is attested in political slang from 1820. Teen slang sense of "extraordinary, wonderful" is from late 1970s (see radical (adj.)).

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Online Etymology Dictionary, © 2010 Douglas Harper

radder in Science


  1. 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.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

radder in Culture


An acronym for radiation absorbed dose. A unit of energy absorbed from ionizing radiation.

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The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.