Definition of roof:
a protective covering that covers or forms the top of a building
protective covering on top of a motor vehicle
the inner top surface of a covered area or hollow space; "the roof of the cave was very high"; "I could see the roof of the bear's mouth"
an upper limit on what is allowed; "he put a ceiling on the number of women who worked for him"; "there was a roof on salaries"; "they established a cap for prices"
provide a building with a roof; cover a building with a roof