Refers to a small piece of furniture for sitting, often a bathroom bench or a simple seat. The cross-reference to 腰掛け suggests it is a compound emphasizing the object as a seating platform.
See also: 腰掛け
I placed a small bench in the bathroom so I can sit down while washing myself.
Having a small seat in the entrance is convenient when putting on shoes.
Standard kanji spelling.
Variant without okurigana け.
Variant with かけ in kana.
Compound of 腰掛け (stool, seat) and 台 (platform, stand). The exact historical derivation is uncertain, but the word transparently means 'sitting platform'.