Bullnose

Bullnose is a term used in building construction for rounded convex trim, particularly in masonry and ceramic tile.

Bullnose trim is used to provide a smooth, rounded edge for countertops, staircase steps, building corners, verandas, or other construction.

[2] When referring to bullnose, it is sometimes modified by adding the word quarter or half.

In the illustration, one piece of quarter-bullnose tile is juxtaposed with a plain piece of tile, to create a finished look — note that the top trim strip shows a quarter-bullnose on two of its sides.

[4] In the 19th century, the roofs of railroad passenger cars often had a raised centre section to improve ventilation and internal lighting.