[ prot-uh-sis ]

noun,plural prot·a·ses [prot-uh-seez]. /ˈprɒt əˌsiz/.
  1. Grammar. the clause expressing the condition in a conditional sentence, in English usually beginning with if.: Compare apodosis.

  2. the first part of an ancient drama, in which the characters are introduced and the subject is proposed.: Compare catastasis, catastrophe (def. 4), epitasis.

  1. (in Aristotelian logic) a proposition, especially one used as a premise in a syllogism.

Origin of protasis

First recorded in 1610–20; from Late Latin: “introduction in a drama,” from Greek prótasis “proposition,” literally, “a stretching forward,” equivalent to pro-pro-2 + tásis a stretching (ta-, verbid stem of teínein “to stretch” + -sis-sis)

Words Nearby protasis Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use protasis in a sentence

British Dictionary definitions for protasis


/ (ˈprɒtəsɪs) /

nounplural -ses (-siːz)
  1. logic grammar the antecedent of a conditional statement, such as it rains in if it rains the game will be cancelled: Compare apodosis

  2. (in classical drama) the introductory part of a play

Origin of protasis

C17: via Latin from Greek: a proposal, from pro- before + teinein to extend

Derived forms of protasis

  • protatic (prɒˈtætɪk), adjective

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