Antonyms of adj dubitable

1 sense of dubitable

Sense 1
doubtful, dubious, dubitable, in question (predicate) -- (open to doubt or suspicion; "the candidate's doubtful past"; "he has a dubious record indeed"; "what one found uncertain the other found dubious or downright false"; "it was more than dubitable whether the friend was as influential as she thought"- Karen Horney)

INDIRECT (VIA questionable) -> unquestionable -- (incapable of being questioned; "unquestionable authority")

Similarity of adj dubitable

1 sense of dubitable

Sense 1
doubtful, dubious, dubitable, in question (predicate) -- (open to doubt or suspicion; "the candidate's doubtful past"; "he has a dubious record indeed"; "what one found uncertain the other found dubious or downright false"; "it was more than dubitable whether the friend was as influential as she thought"- Karen Horney)
       => questionable (vs. unquestionable) -- (subject to question; "questionable motives"; "a questionable reputation"; "a fire of questionable origin")