RhymeZone: ceil definitions

Definitions of ceil:

verb: (transitive) To line or finish (a surface, such as a wall), with plaster, stucco, thin boards, or similar.
noun: (poetic) A ceiling.
verb: (mathematics) To set a higher bound.
noun: (mathematics) Abbreviation of ceiling. [The overhead closure of a room.]

(Definitions from Wiktionary)