Having or showing excessive and arrogant self-confidence; presumptuous.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "presuming" in a sentence
"Your letter was, if possible, received with more than usual warmth for I was not a little anxious to hear from you notwithstanding I of course knew the cause of your delay -- And you were right in presuming I would pardon you, for how could I ever do otherwise when you always have a very good excuse and are ever generous to pardon me."
"I give little credence in presuming the human practice of organizing thought processes as providing insight into the ultimate reality (Who knows the Truth?)."
"Perhaps in presuming to take some laws more seriously than others I am on a slippery slope. alex."