Trinity Sunday WORD ORIGIN noun the Sunday after Pentecost, observed as a festival in honor of the Trinity. Liberaldictionary.com
Origin of Trinity Sunday late Middle English word dating back to 1400–50 Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019 British Dictionary definitions for trinity sunday Trinity Sunday noun the Sunday after Whit Sunday Collins English Dictionary – Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012