wheth·er (wĕthər, hwĕth-)
1. Used in indirect questions to introduce one alternative: We should find out whether the museum is open. See Usage Notes at doubt, if.
2. Used to introduce alternative possibilities: Whether she wins or whether she loses, this is her last tournament.
3. Either: He passed the test, whether by skill or luck.
Which: "We came in full View of a great Island or Continent, (for we knew not whether)" (Jonathan Swift).
whether or no
Regardless of circumstances.
[Middle English, from Old English hwether; see kwo- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.