caltrop

• POS: Noun
• HYPHEN: cal=trop

CIDE DICTIONARY

caltrop, n. [OE. calketrappe, calletrappe, caltor (in both senses), fr. AS. collræppe, 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.].

•  A genus of herbaceous plants (Tribulus) of the order Zygophylleæ, 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.  [1913 Webster]
•  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.  [1913 Webster]

OXFORD DICTIONARY

caltrop, n. (also caltrap)
1 hist. a four-spiked iron ball thrown on the ground to impede cavalry horses.
2 Heraldry a representation of this.
3 any creeping plant of the genus Tribulus, with woody carpels usu. having hard spines.

Etymology

(sense 3) OE calcatrippe f. med.L calcatrippa: (senses 1-2) ME f. OF chauchetrape f. chauchier tread, trappe trap: ult. the same word