one who sums; one who casts up an account.-a large stone or beam placed horizontally on columns, piers, posts, or the like, serving for various uses. specifically: (a) the lintel of a door or window. (b) the commencement of a cross vault. (c) a central floor timber, as a girder, or a piece reaching from a wall to a girder. called also summertree.-the season of the year in which the sun shines most directly upon any region; the warmest period of the year.-to pass the summer; to spend the warm season; as, to summer in switzerland.-to keep or carry through the summer; to feed during the summer; as, to summer stock.