triplet
trip-let
noun
One of three children born at the same birth to the same mother.
"She's expecting triplets next month."
noun
A set of three similar items or people considered as a group.
"The artist created a triplet of sculptures."
Thesaurus
Synonyms: threesome, troika, tercet, three, deuce-ace, trinity, III, triad, tierce, trine, 3, ternary