Why was "tantrum" trending last week?
1610s, "spread in all directions from a point," from Latin radiatus, past participle of radiare "to beam, shine, gleam; make beaming" (see radiation). Meaning "be radiant, give off rays (of light or heat)" is from 1704. Related: Radiated; radiates; radiating.
"having rays, furnished with rays, shining," 1660s, from Latin radiatus (see radiate (v.)).
radiate ra·di·ate (rā'dē-āt')
v. ra·di·at·ed, ra·di·at·ing, ra·di·ates
To spread out in all directions from a center.
To emit or be emitted as radiation.