3. Any symbol of the Trinity employed in Christian art, especially the triangle. Trinity house, an institution in london for promoting commerce and navigation, by licensing pilots, ordering and erecting beacons, and the like. Trinity Sunday, the Sunday next after whitsunday; so called from the feast held on that day in honor of the holy Trinity. Trinity term.
Origin: OE. Trinitee, F. Trinite, L. Trinitas, fr. Trini three each. See Trinal.