Triplet
From BiblePortal Wikipedia
Webster's Dictionary [1]
(1): ( n.) A collection or combination of three of a kind; three united.
(2): ( n.) A group of three notes sung or played in the tree of two.
(3): ( n.) Three children or offspring born at one birth.
(4): ( n.) Three verses rhyming together.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]
a window of three lights. Many such occur in the First Pointed style, the center light being usually longer or more elevated than the two side lights.