Presume is used when someone is making an informed guess based on reasonable evidence. Assume is used when the guess is based on little or no evidence. Presume functions a little differently in the legal catchphrase "presumed innocent until proven guilty." That sense of presume is separately defined as "to suppose to be true without proof."
If you are presumed to be the fastest runner, don't get too cocky — that word implies that you haven't actually raced yet. To presume is to take something for granted.
PRESUMED definition: 1. past simple and past participle of presume 2. to believe something to be true because it is very…. Learn more.
To venture without authority or permission; dare: He presumed to invite himself to dinner. 1. To take for granted that something is true or factual; make a supposition. 2. To act presumptuously or take unwarranted advantage of something: Don't presume on their hospitality.
take for granted: [~ + object] We presume his innocence. [~ + object (+ to + be) + adj] We presume him (to be) innocent. [~ + object + to + verb] They presumed him to be hiding in Amsterdam. [~ + (that) clause] I presume you're coming to the play with us, aren't you?
presume (third-person singular simple present presumes, present participle presuming, simple past and past participle presumed) I don't want to pretend to be an authority on this line of business, so I would never presume to tell you how to run your own company.
to take as a matter of fact without questioning or without proof; take for granted; assume. He presumed that his girlfriend would help him with the project. She was wearing a white coat, so I presumed she was the doctor. to take on (some action) without authority or invitation.