[ 'si:lɪŋ ]
■ noun
1》 the upper interior surface of a room.
2》 an upper limit set on prices, wages, etc.
3》 the maximum altitude that an aircraft can reach.
↘the altitude of the base of a cloud layer.
4》 the inside planking of a ship's bottom and sides.
Origin
ME: from ceil + -ing 1 .