/truy lem"euh/ , n.
1. a situation, analogous to a dilemma, in which there are three almost equally undesirable alternatives: His trilemma consisted in not knowing whether to acknowledge receipt, deny it, or simply leave.
2. Logic. a form of argument in which three choices are presented, each of which is indicated to have consequences that may be unfavorable.
[ 1665-75; TRI- + (DI)LEMMA ]