also: かいだんタンス
noun
staircase chest of drawers
A piece of furniture combining drawers and steps, used to access a loft or raised area while providing storage.
ロフトに上がるために階段箪笥を使っている。
I use a staircase chest of drawers to get up to the loft.
箪笥 is a general chest of drawers; 階段箪笥 specifically has a staircase-like structure.
Compound of 階段 (stairs) and 箪笥 (chest of drawers), describing a dual-purpose furniture piece.