The prisoner was quietly reading a book in the cell.
The new cell is a little larger than the previous one.
牢屋 is a more colloquial and broader term for jail or prison as a whole, whereas 監房 refers specifically to the cell itself.
single-person cell; solitary confinement cell
Standard kanji spelling for a prison cell.
Rarely used kanji form; 監房 is preferred.
Compound of 監 (かん, 'watch, oversee') and 房 (ぼう, 'chamber, room'), literally 'watch chamber'. The exact historical derivation is uncertain, but the spelling is conventionally associated with a prison cell.