Cheval-de-frise

(n.) A piece of timber or an iron barrel traversed with iron-pointed spikes or spears, five or six feet long, used to defend a passage, stop a breach, or impede the advance of cavalry, etc.

Thesaurus Entries

advanced work, balistraria, bank, banquette, barbed-wire entanglement, barbican, barricade, barrier, bartizan, bastion, battlement, breastwork, bulwark, casemate, cheval-de-frise, circumvallation, contravallation, counterscarp, curtain, demibastion, dike, drawbridge, earthwork, enclosure, entanglement, escarp, escarpment, fence, fieldwork, fortalice, fortification, glacis, loophole, lunette, machicolation, mantelet, merlon, mound, outwork, palisade, parados, parapet, portcullis, postern gate, rampart, ravelin, redan, redoubt, sally port, scarp, sconce, stockade, tenaille, vallation, vallum, work