undoubtably

Etymology
From, equivalent to.

Adverb

 * 1)  Without doubt; indubitably, undoubtedly.

Usage notes

 * "Undoubtably" is considered to be nonstandard English by some authorities (for example, Garner's Modern American Usage (2009)), and the term is seldom found in modern literary writing. The Oxford English Dictionary provides no examples of usage after 1513 and characterizes "undoubtably" as "? Obs.," wondering whether the term is obsolete. Nevertheless, many examples of its usage can be found in 20th- and 21st-century popular English and in contemporary academic journals. Its persistence in use may reflect that some writers wish to draw an epistemic differentiability between the idea of "I don't doubt X" or "hardly anyone doubts X"  versus "it is impossible or nonsensical to doubt X", where the latter is a stronger category of dubiousness (this differentiation is analogous to that between, for example,  and ). But the desired differentiation is not well established or standard.