Dictionary entry

Ravelin

Webster's Dictionary 1913

Rave″lin (răv″lĭn; 277), n. [F.; cf. Sp. rebellin, It. revellino, rivellino; perhaps fr. L. re- again + vallum wall.] (Fort.) A detached work with two embankments which make a salient angle. It is raised before the curtain on the counterscarp of the place. Formerly called demilune, and half-moon.