Definition of weatherboard

• n. - That side of a vessel which is toward the wind; the windward side.
• n. - A piece of plank placed in a porthole, or other opening, to keep out water.
• n. - A board extending from the ridge to the eaves along the slope of the gable, and forming a close junction between the shingling of a roof and the side of the building beneath.
• n. - A clapboard or feather-edged board used in weatherboarding.