'Triune' definitions:

Definition of 'triune'

(from WordNet)
adjective
Being three in one; used especially of the Christian Trinity; "a triune God"

Definition of 'Triune'

From: GCIDE
  • Triune \Tri"une\, a. [Pref. tri- + L. unus one. See One.] Being three in one; -- an epithet used to express the unity of a trinity of persons in the Godhead. [1913 Webster]