trin ‧ i ‧ ty /ˈtrɪnəti, ˈtrɪnɪti/ BrE AmE noun
[ Date: 1200-1300 ; Language: Old French ; Origin: trinité , from Latin trinitas , from trinus 'existing as three' ]
the Trinity ( also the holy Trinity ) in the Christian religion, the union of Father, Son, and Holy Spirit in one God