binitas

From bīnī (“two each”) +‎ -tās.

• (Classical Latin) IPA^(key): [ˈbiː.nɪ.taːs]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈbiː.ni.t̪as]

bīnitās f (genitive bīnitātis); third declension (Late Latin)

1. (rare) duality; twoness; the state of being two

   Synonym: duālitās

2. (Ecclesiastical Latin, theology, historical) the Binity (the binitarian belief in the two persons of the Godhead: the Father and the Son; rejected as heretical following the First Council of Constantinople in 381 C.E., which extended the Nicene Creed to confirm the divine nature of the Holy Spirit)

Third-declension noun.