the structure forming the upper covering of a building or vehicle

the rain woke him, hammering on the roof

a thatched roof

a car with a vinyl roof

roof timbers

the upper limit or level of prices or wages

starting salary £12,185, rising to a roof of £16,835

cover with a roof

the yard had been roughly roofed over with corrugated iron

A four-year prison sentence.

Originally: (the sum of) four shillings (disused after the introduction of decimal coinage to Britain in 1971). Now: four pounds sterling.