legless chair; floor chair
A chair without legs, designed for sitting on tatami flooring; often has a backrest and sometimes armrests.
和室に座椅子を置いて使っている。
I use a legless chair in the Japanese-style room.
座椅子に座ってテレビを
I sit on a floor chair and watch TV.
座布団 is a simple flat floor cushion, whereas 座椅子 is a legless chair with a backrest for floor sitting.
Standard kanji spelling.
Mixed kanji-kana spelling, also common.
Rarely used kanji form; 坐 is an older variant of 座.
Formed from 座 “sitting, seat” and 椅子 “chair,” denoting a chair designed for sitting directly on a floor and therefore lacking ordinary legs.