Category:Ravelin (Architecture)

Rave"lin, n. Etym: [f.; cf. Sp. rebellin, it. revellino, rivellino; Perhaps fr. L. re- again + vallum wall.] (fort.)

Defn: 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.