ravelin

plural ravelins

1. A kind of outwork; a freestanding, wedge-shaped fortification used to split an attacking force as they approach a larger fortress.

   2 more examples

   I think, quoth Corporal Trim, with humble submission to your Honour’s better judgment,——that these ravelins, bastions, curtins, and hornworks, make but a poor, contemptible, fiddle-faddle piece of work of it here upon paper, compared to what your Honour and I could make of it were we in the country by ourselves, and had but a rood, or a rood and a half of ground to do what we pleased with: As summer is coming on, continued Trim, your Honour might sit out of doors, and give me the nography—(Call it ichnography, quoth my uncle,)——of the town or citadel, your Honour was pleased to sit down before,—and I will be shot by your Honour upon the glacis of it, if I did not fortify it to your Honour’s mind.

   1659, Laurence Sterne, chapter XXX, in The Life and Opinions of Tristram Shandy, Gentleman

   It is about 2,500 yards in circuit, is built of red stone, and, according to Von Orlich, is now " a bastioned quinquangle ; the ancient walls with semicircular bastions face the two streams ; the land side is quite regular, and consists of two bastions, and a half-bastion with three ravelins," and stands higher than any ground in face of it.

   1858, Edward Thornton, A Gazetteer of the Territories Under the Government of the East India Company and of the Native States on the Continent of India, W. H. Allen & Co., page 22