Where Does the Word Indubitably Come from?

There's no reason to question the fairly straightforward etymology of indubitable - a word that has remained true to its Latin roots. It arrived in Middle English in the 15th century from Latin indubitabilis, itself a combination of "in-" ("not") and "dubitabilis" ("open to doubt or question").

Is indubitably a real word?

Indubitably is an adverb that means “impossible to doubt.” It has a meaning similar to doubtless and undoubtedly, but it represents a much stronger degree of certainty.

Is indubitably in the dictionary?

in a way that is patently evident or certain; unquestionably; without doubt: A week at the spa has indubitably improved his health.