Other forms: ceilings
The ceiling is the surface above your head inside a room. Usually white, and noticed only when it needs painting.
It is the underside of the floor above, or of the roof if there is nothing above. The word gives English one of its most useful metaphors for limits, since a price ceiling and a debt ceiling are both upper bounds, and the glass ceiling is the invisible barrier that stops women and minorities rising past a certain level. Hitting the ceiling means losing your temper, which is the same image as hitting the roof.
A ceiling is a concealment. Middle English celing meant panelling, from Old French celer, to hide, because the point of it was to cover the beams up.
Old French
celer — to conceal
Middle English
celing — paneling; (bed) cover or hanging
English, today
ceiling
Built from
From Middle English celing (“paneling; (bed) cover or hanging”), from celen (“to cover or panel walls”) (from Old French celer (“to conceal”)) + -ing. by surface analysis, ceil + -ing.
Etymology from Wiktionary, CC BY-SA