A difficult circumstance or problem.
A type of syllogism of the form "if A is true then B is true; if C is true then D is true; either A or C is true; therefore either B or D is true".
A circumstance in which a choice must be made between two or more alternatives that seem equally undesirable.
Offering to an opponent a choice between two (equally unfavorable) alternatives.
The state or quality of being perplexed; puzzled or confused.
Something that perplexes.
In information theory, a measurement of how well a probability distribution or model predicts a sample.