According to Peter Kreeft and Ronald Tacelli in Handbook of Christian Apologetics (Downers Grove, Illinois: InterVarsity Press, 1994), truths can be classified according to the following schema (where F = truths known by faith alone, and R = truths known by reason alone; see p. 35 of Handbook).
The area of overlap would describe those truths that can be discovered at least somewhat by reason alone, but that can be known much more clearly when aided by the light of faith. I believe that morality and, more generally, natural law would fall into this overlap category.
I enjoy applying the following names to the three categories of truths delineated by this schema: “Catholic” for those truths known only by faith; “All Truth is God’s Truth” for those truths known only by reason; and “All Divisions Shall Cease” for the overlap region. All three of those terms point to the eventual dissolution of all such schemata when God will be All in All (for even “Catholic” means “universal”).