n. pl. prot·a·ses (-sēz′)
1. Grammar The dependent clause of a conditional sentence, as if it rains in The game will be canceled if it rains.
2. The first part of an ancient Greek or Roman drama, in which the characters and subject are introduced.
[Late Latin, proposition, first part of a play, from Greek, premise of a syllogism, conditional clause, from proteinein, prota-, to propose : pro-, forward; see PRO-2 + teinein, to stretch; see ten- in the Appendix of Indo-European roots.]
pro·tatic (prŏ-tătĭk, prō-) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.