The term "eave" stands for the edges of a roof which overhang the face of a wall and normally project beyond the side of a building. The word "eave" itself does not stand for an acronym but is derived from the Old English word "efes," meaning "edge".
In architecture, eaves serve the primary function of directing rainwater away from the walls and protecting the building from water damage, while also providing shading and enhancing the building's aesthetics. The term is almost always used in the plural form, "eaves".
Hence, "eave" refers to the overhanging edge of a roof, not an acronym or abbreviation.