Whitsun
noun
"1909: Sidney Heath, Romance of Symbolism: Fonts and the symbols of baptism - The times [for baptism] of which Whitsun Eve is one, are specified by ... the constitutions for Orthobon for England, Gerona, 517, c. iv."
°The holiday beginning on Whitsunday.
adjective
°Of, or relating to Whitsunday or Whitsuntide.
synonyms: whitsuntide, whitweek, pentecost