Refers to the floor above the current one, or the upstairs area in general. Antonym: 階下 (かいか, downstairs).
Antonyms: 階下
I can hear noises from the room upstairs.
top of the stairs
Specifically the landing or area at the top of a staircase. Antonym: 階下 (かいか, bottom of the stairs).
Antonyms: 階下 (かいか)
The cat is sleeping at the top of the stairs.
lower floor; downstairs · bottom of the stairs; foot of the stairs
Compound of 階 (かい, 'floor, storey') and 上 (じょう, 'upper, above'). The reading じょう is a standard on'yomi for 上 in compounds.