1. Likely to happen or to be true: War seemed probable in 1938. The home team, far ahead, is the probable winner.
2. Likely but uncertain; plausible.
3. Theology Of or relating to opinions and actions in ethics and morals for whose lawfulness intrinsic reasons or extrinsic authority may be adduced.
[Middle English, plausible, from Old French, from Latin probābilis, from probāre, to prove; see PROVE.]
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.