A unit of absorbed radiation dose equal to one one-hundredth of a gray, used in measuring radiation exposure.
From 'rad,' which itself comes from 'radiation absorbed dose.' The 'd-' prefix is occasionally added for emphasis in older scientific literature, though 'rad' alone is the standard term.
The rad was the original unit for measuring radiation before scientists created the 'gray'—which is exactly 100 times larger, showing how our understanding of safe radiation exposure has dramatically changed over decades.
Complete word intelligence in one call. Free tier — 50 lookups/day.