triadic

adjective4

1. •
   Of or relating to a triad.
2. •
   Having an arity of three; taking three arguments or operands.
3. •
   Being or relating to interpreting that involves three parties, i.e. the two clients and the interpreter.

   • The notion that one is doing a worthwhile job and the interpretation of just what kinds of intervention are possible are key in the issues of triadic interpreting... — 2008
4. •
   (no longer used) Trivalent.