\Prot"a*sis\, n. [L., fr. Gr. ?, fr. ? to stretch
before, forward; ? before + ? to stretch.]
1. A proposition; a maxim. --Johnson.
2. (Gram.) 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.