noun ·see the note under term, ·noun, 12.
2. whitsunday ·noun the seventh sunday, and the fiftieth day, after easter; a festival of the church in commemoration of the descent of the holy spirit on the day of pentecost; pentecost;
so called, it is said, because, in the primitive church, those who had been newly baptized appeared at church between easter and pentecost in white garments.