"Presume on" is an idiomatic expression that means taking advantage of someone or something. Some synonyms for presume on include exploit, take advantage of, abuse, misuse, manipulate, and leverage. Exploit connotes taking undue advantage for personal gain, while take advantage of refers to using a situation to one's benefit. Abuse implies using power or resources wrongfully, while misusing indicates using something in an incorrect manner. Manipulate suggests using cunning methods to control or influence. Leverage highlights using something to gain an advantage. Employing synonyms for presume on can help convey a more nuanced meaning in the context of the sentence.