A notched board that supports the treads and risers of wooden stairs.

1. A structure that spans a depression or provides a passage between two points which are at a height above

A joint designed to permit relative movement between a brick wall and its adjacent structure without impairing the functional integrity

A cube of brickwork, 9 in., (22.86 cm) on each side, used widely for quality control tests in Great Britain

An isolated vertical loadbearing member whose width is not more than four times its thickness.