Definition of "whether" []

• Used in indirect questions to introduce one alternative: We should find out whether the museum is open. See Usage Notes at doubt, if. (conjunction)
• Used to introduce alternative possibilities: Whether she wins or whether she loses, this is her last tournament. (conjunction)
• Either: He passed the test, whether by skill or luck. (conjunction)
• Archaic Which: "We came in full View of a great Island or Continent, (for we knew not whether)” ( Jonathan Swift). (pronoun)
• Whether or no Regardless of circumstances. (idiom)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Having begun to illustrate the distinction between inquiry if or whether something is and what it is with the question ˜whether there is or is not a centaur or a god™, he then characterizes the knowledge achieved as ˜knowing that it is™."
• "But when we are considering the question whether Bathurst and Lowe were needlessly strict or not, the point at issue is _whether plans of escape or rescue existed, and if so, whether they knew of them_."
• "This being so, if you doubt the other branch of the proposition, whether he is for you, —whether he is really for you, as I have expressed it, —I propose asking your attention for a while to a few facts."