(1):

(n.) The wedging, as of a horse or car, against the top of an underground passage.

(2):

(p. pr. & vb. n.) of Roof

(3):

(n.) Hence, the roof itself; figuratively, shelter.

(4):

(n.) The act of covering with a roof.

(5):

(n.) The materials of which a roof is composed; materials for a roof.