D defs.my
Entry 3 senses Webster, 1913

Protasis

/(prŏt"ȧ*sĭs)/ · Prot·a·sis · IPA /ˈpɹɒtəsɪs/
01 n. A proposition; a maxim.
  1. 1.
    A proposition; a maxim.
  2. 2.
    The introductory or subordinate member of a sentence, generally of a conditional sentence; -- opposed to apodosis. See Apodosis.(Gram.) See: Apodosis
  3. 3.
    The first part of a drama, of a poem, or the like; the introduction; opposed to epitasis.