Home Help Word English Spanish French Russian German Italian Chinese (Trad.) Chinese (Simpl.) Portuguese Arabic Turkish Greek » Definition of " Trilemma " in English English Dictionary Results Trilemma A syllogism with three conditional propositions, the major premises of which are disjunctively affirmed in the minor. See Dilemma. n. Trilemma A state of things in which it is difficult to determine which one of three courses to pursue. n.