Meaning

verb send out rays or waves

verb send out real or metaphoric rays

verb extend or spread outward from a center or focus or inward towards a center

originLearned borrowing from Latin radiātus, perfect passive participle of radiō (“to radiate, furnish with spokes, give out rays, radiate, shine”) (see -ate (verb-forming suffix)), from radius (“a spoke, ray”).

Etymology from Wiktionary, CC BY-SA 3.0