Arabic 'al-qubbah' (the vault) traveled through Spanish bedrooms to become an English architectural niche.
A recess in the wall of a room, or a small section of a room set back from the main area, often used for a bed, seating, or display.
From French 'alcôve,' from Spanish 'alcoba' (a bedroom, an alcove), from Arabic 'al-qubbah' (the vault, the dome, the arched recess), from 'qubbah' (a vault, a dome, a tent with an arched top). The Arabic article 'al-' was absorbed into the borrowed word, as in many Arabic-to-European loanwords. The original Arabic sense of a vaulted or domed recess — a niche set into a wall — transferred in Spanish to a recessed sleeping area in a room, then entered French and English as a general term for any recess in a wall or room.
The Arabic word 'qubbah' (dome, vault) — the source of 'alcove' — also gave its name to the Dome of the Rock in Jerusalem, known in Arabic as 'Qubbat al-Sakhra.' The same word that describes a small recess in a Western bedroom also names one of the most famous domed structures on earth.