Casually assume possession.

The one who accompanied the first party of explorers confused Lazarus and Barstow by assuming casually that he had met them before, that he had visited them in the ship.

Their hands rested on the belts near the boxes in an attitude so casually assumed that it seemed to be only a part of their stance, but Kirk was wary.

It can actually serve humanity by making it harder for any of us to casually assume our own goodness.

Scott assumed casually that he was dead.

Whilst he had always casually assumed their protection, he had never wholly trusted them.

Gaia casually assumed that I included my ship; that we were a unit.

Romiss seemed to be casually assuming a rather high degree of intelligence in the Feathered Ones.

If I wake up casually assuming that I can go bang out nine miles, easy peasy.

He casually assumed himself to be worth whole squadrons.