(of a person or their behavior) failing to observe the limits of what is permitted or appropriate:

｟けなして｠ ; 〖通例be ～〗 〈人･行為などが〉厚かましい, でしゃばった; 高慢な

e.g. I hope I won't be considered presumptuous if I offer some advice.

presumptuously |prəˈzəm(p)(t)SH(o͞o)əslē| adverb

presumptuousness |prəˈzəm(p)(t)SH(o͞o)əsnəs| noun

Middle English: from Old French presumptueux, from late Latin praesumptuosus, variant of praesumptiosus ‘full of boldness’, from praesumptio (see presumption).