Definition of breastsummer

• n. - A summer or girder extending across a building flush with, and supporting, the upper part of a front or external wall; a long lintel; a girder; -- used principally above shop windows.
• n. - A summer or girder extending across a building flush with, and supporting, the upper part of a front or external wall; a long lintel; a girder; -- used principally above shop windows.