indubitably

indubitable +‎ -ly

• (Received Pronunciation) IPA^(key): /ɪnˈdjuː.bɪ.tə.bli/
• (General American) IPA^(key): /ɪnˈdu.bɪ.tə.bli/

• Audio (US)

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indubitably (comparative more indubitably, superlative most indubitably)

1. In a manner that leaves no possibility of doubt; undoubtedly.
   • 1871, Thomas Hardy, chapter 18, in Desperate Remedies:

     Now his first suspicion was indubitably confirmed.

   • 1907, William James, Pragmatism: A New Name for Some Old Ways of Thinking:

     The world is indubitably one if you look at it in one way, but as indubitably is it many, if you look at it in another. It is both one and many—let us adopt a sort of pluralistic monism.

   • 1913, Arthur Conan Doyle, “(please specify the page)”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton, →OCLC:

     They were all indubitably, aggressively alive! Everybody was alive once more!

Currently particularly used as a humorous interjection, particularly in American English, and seen as somewhat affected, if not outright haughty or campy. Compare this use by comedy cartoon Goofy Gophers (US, 1947–65).

• undoubtably, undoubtedly, unquestionably, doubtlessly, assuredly, certainly, sure thing, without a doubt

• indubitable

• “indubitably”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “indubitably”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present.
• Oxford English Dictionary, 2nd ed., 1989.