ceiling / sealing [ˈsi:lɪŋ]
ceiling – n. – 1. the upper interior surface of a room or other similar compartment – the material forming this; 2. an upper limit on prices, wages, performance, etc.; 3. the altitude of the base of a cloud layer
sealing – adj. – describing something used to seal; v. pres. part. – 1. hunting; 2. applying a non-porous coat (i.e. of paint); 3. securing (as with plastic containers, or buildings, rooms, etc., for criminal investigation)