protasis

protasis is a   Noun

Definition:

[1] A proposition; a maxim. Johnson.

[2] The introductory or subordinate member of a sentence, generally of a conditional sentence; -- opposed to apodosis. See Apodosis.

[3] The first part of a drama, of a poem, or the like; the introduction; opposed to epitasis. B. Jonson.

Synonyms: