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
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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