席を立ちかけて腰を浮かした。の英語

I half rose to my feet to leave my seat.

I excused myself from the table.

I left the table before I had finished the meal.

He lifted himself heavily [heaved himself] out of his chair.

Then he stretched his legs and settled back in his seat.

I sat waiting on the bench.

They have reserved a seat―kept a seat―for me.

He sank into a chair.

I was away from my desk.

I sat waiting on the bench.

I'm sitting on the sofa.

lean back in one's chair

It was good of you to give up your seat.

He is sitting on a chair―seated in a chair.

Take a seat in the armchair and calm down a while.

We sat in the seat at the very back.

Two seats remained vacant.

I sat with my elbows resting on the desk.

He leaned back in his chair, lost in thoughts.

I ended up losing my balance and fell from the chair.

Utterly wearied, I slumped into the chair.

I excused myself for a minute.

I was ushered to my seat.

get up from a sitting or slouching position

He seated himself on the bench.

I exchanged seats with her.

And then I fell asleep while sitting up.

May I put my seat back?

I was sitting in the very back.

He was leaning on his desk and dozing―dozing on his desk.