1 assume, take for granted, suppose, surmise, infer, suppose, presuppose, take it, gather, understand, think, believe, imagine, suspect, fancy, conjecture, postulate, posit, theorize, speculate, hypothesize, hypothecate, US and Canadian guess:
For some unaccountable reason, we presumed that your train would arrive on time. Dr Livingstone, I presume?
2 dare, take the liberty, be so presumptuous as, make (so) bold (as), have the audacity or effrontery, go so far as, venture:
Who is he to presume to judge others?
3 Often, presume on or upon. encroach (on or upon), impose (on or upon), take liberties (with), intrude (on or upon or into):
I hate to presume on our friendship, but could you lend me some money?