1. (n.) One who sums; one who casts up an account.

2. (n.) 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.

3. (n.) The season of the year in which the sun shines most directly upon any region; the warmest period of the year.

4. (v. i.) To pass the summer; to spend the warm season; as, to summer in Switzerland.

5. (v. t.) To keep or carry through the summer; to feed during the summer; as, to summer stock.