expression, godan verb (-su)
half-rise from one's seat
Describes lifting one's hips slightly off a seat, often in preparation to stand or as a polite gesture.
彼は驚いて腰を浮かした。
He half-rose from his seat in surprise.
お客さんが来たので、ソファから腰を浮かして挨拶した
When the guest arrived, I lifted myself slightly off the sofa to greet them.