adv. 25B6; adverb DOUBTLESS, indubitably, doubtlessly, no doubt, without (a) doubt; unquestionably, indisputably, undeniably, incontrovertibly, clearly, obviously, patently, certainly, definitely, surely, of course, indeed.
UNDOUBTEDLY
Meaning of UNDOUBTEDLY in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012