The Collaborative International Dictionary
Caltrop \Cal"trop\, Caltrap \Cal"trap\, n. [OE. calketrappe, calletrappe, caltor (in both senses), fr. AS. collr[ae]ppe, calcetreppe, sort of thistle; cf. F. chaussetrape star thistle, trap, It. calcatreppo, calcatreppolo, star thistle. Perh. from L. calx heel + the same word as E. trap. See 1st Trap.]
(Bot.) A genus of herbaceous plants ( Tribulus) of the order Zygophylle[ae], having a hard several-celled fruit, armed with stout spines, and resembling the military instrument of the same name. The species grow in warm countries, and are often very annoying to cattle.
(Mil.) An instrument with four iron points, so disposed that, any three of them being on the ground, the other projects upward. They are scattered on the ground where an enemy's cavalry are to pass, to impede their progress by endangering the horses' feet.
Wiktionary
n. (archaic form of caltrop English)
Usage examples of "caltrap".
As an afterthought he opened his sock drawer and took a pistol crossbow, a flask of oil, a roll of lockpicks and, after some consideration, a punch dagger, a bag of assorted caltraps and a set of brass knuckles.
Three knives of deadly sharpness and varying size were concealed about his person, together with a bag full of small caltraps that could bring a charging horse to a halt.