Weatherboard
Weatherboard , noun
1.
(a) (Nautical) That side of a vessel which is toward the wind; the windward side.
(b)
(Nautical) A piece of plank placed in a porthole, or other opening, to keep out water.
2.
(a) (Architecture) 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.
(b)
(Architecture) A clapboard or feather-edged board used in weatherboarding.