Definition of caltrop
1a caltrops also calthrops plural in form but singular or plural in construction : star thistle 1b : puncture vine; also : any of various related herbs (genera Tribulus and Kallstroemia) of the same family (Zygophyllaceae, the caltrop family)
2 : a device with four metal points so arranged that when any three are on the ground the fourth projects upward as a hazard to the hooves of horses or to pneumatic tires
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Origin and Etymology of caltrop
Middle English caltrappe, alteration of calketrappe star thistle, from Old English calcatrippe, from Medieval Latin calcatrippa
First Known Use: 15th century
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