definitely /ˈdɛf.ɪ.nɪt.li/ adverb2 •without any doubt, used to say that the speaker is sure something is true or will happenJoe definitely doesn't know how to drive a tractor.She said she wasn't coming, definitely. •In a definite manner; decisively.It was really impossible on board that ship to get away definitely from Almayer — 1912 formsmore definitely · most definitely