(Latin for "tile"), in architecture the term given to the covering tile of the ancient roof: the plain tile is turned up on each side and the imbrex covers the joint. In the simpler type of roof the imbrex is semicircular, but in some of the Greek temples it has vertical sides and an angular top. In the temple of Apollo at Bassae, where the tiles were in Parian marble, the imbrex on one side of the tile and the tile were worked in one piece out of the solid marble.