1a (of a person or their behaviour) failing to observe the limits of what is permitted or appropriate.
1b overstepping due bounds (as of propriety or courtesy) : taking liberties
1c too confident especially in a way that is rude : done or made without permission, right, or good reason
Professor Stegner mistook me, I fear, for an anti-intellectual, not understanding that I was in fact something far less presumptuous - a near-illiterate, especially compared to the rest of his blue-chip roster. (Ken Kesey, Remember This: Write What You Don't Know, New York Times, 1989)
But in the same way that western settlers came to the real American frontier seeing an empty landscape, Barlow’s metaphor making was presumptuous. (Jesse Jarnow, The Ghost of John Perry Barlow Lives in His Posthumous Memoir, Wired, 2019)
It would be presumptuous of me to declare anyone the next great player, for only time decides these questions. (Matthew Shipp, Pianist Matthew Shipp Says Goodbye To Tenor Colossus David S Ware, 2012)
"I am not so presumptuous as to believe that," said he, "though you tell it me; but if it were so, I am rather particular in my notions of a companion for life, and perhaps I might not find one to suit me among the ladies you mention." (Anne Bronte, Agnes Grey)
mid-14c, from Old French presumtuex (12c; Modern French présomptueux) and directly from Late Latin praesumptuosus, variant of praesumptiosus, from past participle stem of Latin praesumere 'anticipate,' in Late Latin, 'assume' (see presumption). (Online Etymological Dictionary)