Synonyms for Trinity (same or very similar meaning)
WordNet sense 1 (the cardinal number that is the sum of one and one and one):
leash, ternary, three, trey, triad, trio, triplet, troika, deuce-ace, III, tercet, ternion, terzetto, tierce, trineWordNet sense 2 (the union of the Father and Son and Holy Ghost in one Godhead):
Blessed Trinity, Holy Trinity, Sacred TrinityFrom the ODE community, based on WordNetadd/edit