'Indubitably' definitions:

Definition of 'indubitably'

From: WordNet
adverb
In a manner or to a degree that could not be doubted; "it was immediately and indubitably apparent that I had interrupted a scene of lovers"; "his guilt was established beyond a shadow of a doubt" [syn: indubitably, beyond doubt, beyond a doubt, beyond a shadow of a doubt]

Definition of 'Indubitably'

From: GCIDE
  • Indubitably \In*du"bi*ta*bly\, adv. Undoubtedly; unquestionably; in a manner to remove all doubt. [1913 Webster]
  • Oracles indubitably clear and infallibly certain. --Barrow. [1913 Webster]