- radiate (adj.)
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- "having rays, furnished with rays, shining," 1660s, from Latin radiatus (see radiate (v.)).
- radiate (v.)
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- 1610s, "spread in all directions from a point," from Latin radiatus, past participle of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius). Meaning "be radiant, give off rays (of light or heat)" is from 1704. Related: Radiated; radiates; radiating.