presumptuous

too bold, forward, or taking too much for granted

Roots

-ous / -ious: full of or marked by a quality
pre-: before, earlier, or in front
sume / sumpt: take, take up, or use up

Other words with the sume / sumpt root

assume: to take as true or take on
consume: to use up or eat
presume: to suppose or take for granted
resume: to begin again or take up again
subsume: to include within a larger category

Presumptuous behavior takes too much upon itself before it has the right.

It felt presumptuous to rewrite the plan before asking the team.

Assume and presume keep the take root visible. Presumptuous adds pre- and -ous: a person takes permission, confidence, or status before it has been earned.