Rāve'lin, n.

noun

(rāv'lin) (Synop., § 130), n. [Fr. ravelin, Sp. rebellin, Pg. rebellin, It. revellino, rivellino, from Lat. re, again, against, and vallum, a rampart, 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.

A labeled diagram of a fortified bastion and its surrounding defensive works.
A A, bastions; b b, curtain; c c, tenailles; d d, caponniere; e, ravelin; F, redoubt in the ravelin; g g, covert way; h h, re-entering places of arms; i i, redoubts in do.; k k, ditch; l l, ditch of ravelin; m m m m, glacis; s s, exterior side; s t, capital.