Assuming

taking too much for granted; presumptuous.
to take for granted or without proof:
to -ssume that everyone wants peace.
synonyms: suppose, presuppose; postulate, posit.
to take upon oneself; undertake:
to -ssume an obligation.
to take over the duties or responsibilities of:
to -ssume the office of treasurer.
to take on (a particular character, quality, mode of life, etc.); adopt:
he -ssumed the style of an aggressive go-getter.
to take on; be invested or endowed with:
the situation -ssumed a threatening character.
to pretend to have or be; feign:
to -ssume a humble manner.
to appropriate or arrogate; seize; usurp:
to -ssume a right to oneself; to -ssume control.
to take upon oneself (the debts or obligations of another).
archaic. to take into relation or -ssociation; adopt.
to take something for granted; presume.
contemporary examples

once again, franco is playing the role of west in the updated version, with rogen -ssuming the guise of kardashian.
seth rogen and james franco parody kanye west and kim kardashian’s vogue cover marlow stern march 21, 2014

so how would this play out in the general-election campaign, -ssuming romney is the nominee?
michael tomasky on how rick santorum nailed mitt on romneycare michael tomasky january 28, 2012

thus the transaction was all geared to -ssuming a specific layer of liability, avoiding an open-ended -ssumption.
where buffett has his money now scott horton november 18, 2008

she has a campaign team to name, -ssuming she runs, and a whole raft of positions yet to take.
hillary clinton’s golden ticket: paid family medical leave michael tomasky july 2, 2014

there is a danger, jones suggests, in -ssuming that the known world is preferable to any alternative.
american dreams, 2003: the known world by edward p. jones nathaniel rich november 25, 2013

historical examples

“it will do him a world of good,” i replied, -ssuming a gayety i did not feel.
the celebrity, complete winston churchill

you are -ssuming that the child does not know its own business, and that you do.
a treatise on parents and children george bernard shaw

my own peculiar position was -ssuming most perplexing phases.
in hostile red joseph altsheler

the danger lies in -ssuming that we shall get on any better.
a treatise on parents and children george bernard shaw

evidently, -ssuming his narrative to be true, it was immediately after mr. mortimer tregennis had left the room.
the adventure of the devil’s foot arthur conan doyle

adjective
expecting too much; presumptuous; arrogant
conjunction
(often foll by that) if it is -ssumed or taken for granted (that): even -ssuming he understands the problem, he will never take any action
verb (transitive)
(may take a clause as object) to take for granted; accept without proof; suppose: to -ssume that someone is sane
to take upon oneself; undertake or take on or over (a position, responsibility, etc): to -ssume office
to pretend to; feign: he -ssumed indifference, although the news affected him deeply
to take or put on; adopt: the problem -ssumed gigantic proportions
to appropriate or usurp (power, control, etc); arrogate: the revolutionaries -ssumed control of the city
(christianity) (of g-d) to take up (the soul of a believer) into heaven
v.

early 15c., -ssumpten “to receive up into heaven” (especially of the virgin mary), also -ssumen “to arrogate,” from latin -ssumere “to take up, take to oneself,” from ad- “to, up” (see ad-) + sumere “to take,” from sub “under” + emere “to take” (see exempt (adj.)).

meaning “to suppose, to take for granted as the basis of argument” is first recorded 1590s; that of “to take or put on (an appearance, etc.)” is from c.1600. related: -ssumed; -ssuming. early past participle was -ssumpt. in rhetorical usage, -ssume expresses what the -ssumer postulates, often as a confessed hypothesis; presume expresses what the presumer really believes.