Lewis Short
trīnĭtas (noun F) : trini
* The number three, a triad (post-class.).
* In gen.: facta exinde trinitas generum est ex trinitate causarum,Tert. adv. Val. 17.
* In partic., the Trinity, Tert. adv. Prax. 3; Cod. Just. 1, 1, 1.
Charlton T. Lewis, Charles Short, A Latin Dictionary