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• rad
  rad

  noun

  a unit of absorbed dose of radiation equal to 0.01 gray: not a standard SI unit, the rad is still used, especially in the U.S., but it is increasingly disfavored.
• rad.
  rad.

  abbreviation

  radical.

rad

¹ American  

[rad] / ræd /

noun

Physics.

1. a unit of absorbed dose of radiation equal to 0.01 gray: not a standard SI unit, the rad is still used, especially in the U.S., but it is increasingly disfavored.

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rad ² American  

[rad] / ræd /

noun

1. Informal. a radical, especially a person with extreme views on political and social issues.

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adjective

radder, raddest

1. Slang. excellent; wonderful; cool.

   a high speed, high energy, totally rad racing game.

rad ³ American  

[rad] / ræd /

abbreviation

Mathematics.

1. radian; radians.

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rad. ⁴ American  

abbreviation

Mathematics.

1. radical.

2. radix.

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rad ¹ British  

symbol

1. radian

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rad ² British  

/ ræd /

noun

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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rad. ³ British  

abbreviation

1. radical

2. radius

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rad Scientific  

/ răd /

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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rad Cultural  

1. An acronym for r adiation a bsorbed d ose. A unit of energy absorbed from ionizing radiation.

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Etymology

Origin of rad¹

First recorded in 1915–20; r(adiation) a(bsorbed) d(ose)

Origin of rad²

First recorded in 1820–25 rad ² for 1; 1975–80 rad ² for 2; shortening of radical

Origin of rad³

First recorded in 1910–15; shortening

Example Sentences

“We believe in respect, kindness, and love. We are huge fans of other women-owned companies, LGBTQIA+ communities, and rad men’s companies too. None of that feels political to us,” she said.

From Slate • Jul. 23, 2024

Here are three potential itineraries for three different kinds of rad dads: those who love the great outdoors, fall head over heels for food and dig the arts.

From Seattle Times • Jun. 1, 2024

Madisynn drops into our lives by way of a "diff dimensh" otherwise known as a hellscape, which she navigates like any other rad party, or her hometown of Fort Lauderdale.

From Salon • Dec. 26, 2022

“That makes this a rad time to do this job, even with whatever is going on in the world.”

From Los Angeles Times • Oct. 11, 2022

“You’ve been here a fraction of the time everyone else has, but you’ve gotten pretty much double the amount of litter off the streets. Pretty rad, Fern.”

From "The Wrong Way Home" by Kate O’Shaughnessy

Related Words

• astonishing
• astounding
• awesome
• breathtaking
• fantastic
• incredible
• marvelous
• outrageous
• phenomenal
• remarkable
• spectacular
• superb
• terrific
• unbelievable