expression, godan verb (-su)
A slightly formal or descriptive expression for sitting down, often implying settling oneself into a seat or onto a surface. Compare 座る (すわる), which is more common and neutral.
See also: 腰を上げる
彼はソファに腰を下ろして、新聞を読み始めた。
He sat down on the sofa and started reading the newspaper.
Please take a seat here.