undoubtably

Mane (Îngilîzî)

Without doubt.

Hevwate

doubtlessly

indubitably

surely

undoubtedly

unquestionably

verily

without a doubt

in all likelihood

undoubting

to be sure

doubtless

undoubtfully

Werger

zweifelsohne

evidentemente

fraglos

indubitabilmente

eindeutig

onverdacht

ongetwijfeld

zweifelsfrei

indubtablement

indubbiamente

unzweifelhaft

indubitablement

zweifellos

ontwijfelbaar

indudablemente

Etîmolojî (Îngilîzî)

Ji Middle English mîras hatiye girtin: undoutably

In summary

From Middle English undoutably, equivalent to undoubtable + -ly.