SG Heritage Dictionary

Tenail [Noun] Webster's Dictionary 1828

In fortification, an outwork consisting of two parallel sides with front, in which is a re-entering angle. It is simple or double.

Tenaille [Noun] Webster's Dictionary 1913

An outwork in the main ditch, in front of the curtain, between two bastions. See Illust. of Ravelin.

Tenaillon [Noun] Webster's Dictionary 1828

In fortification, tenaillons are works constructed on each side of the ravelins, like the lunets, but differing in this, that one of the faces of the tenaillon is in the direction of the ravelin, whereas that of the lunet is perpendicular to it.

Tenaillon [Noun] Webster's Dictionary 1913

A work constructed on each side of the ravelins, to increase their strength, procure additional ground beyond the ditch, or cover the shoulders of the bastions.