Dictionary.net

The first part of a drama, of a poem, or the like; the introduction; opposed to epitasis.

A proposition; a maxim; the antecedent clause of a conditional proposition; the first part of an ancient drama, in which the audience were introduced to the characters and the plot.

In gram. and rhet., the first or subordinate member of a sentence, generally conditional the second being called the apodosis; in the anc. drama, the first part, containing an exposition of the subject.

n. [Greek] A proposition ; a maxim ; the preliminary part of a regular sentence ; - the antecedent term of a proposition.