[ kal-truhp ]
/ ˈkæl trəp /


any of several plants having spiny heads or fruit, as those of the genera Tribulus and Kallstroemia, or the star thistle, Centaurea calcitrapa.
an iron ball with four projecting spikes so disposed that when the ball is on the ground one of them always points upward: used to obstruct the passage of cavalry, armored vehicles, etc.



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Also cal·throp [kal-thruhp], /ˈkæl θrəp/, caltrap.

Origin of caltrop

before 1000; Middle English calketrappe,Old English calcatrippe, colte-træppe, equivalent to calce- (<Latin calci-, stem of calx spur, heel) + træppetrap1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for caltrop

  • Sooner or later, the worm forsakes this kind of caltrop which catches on to everything.

    The Life of the Fly|J. Henri Fabre
  • A telegram was accordingly despatched to Mrs. Caltrop, asking her to forward the address of the doctor in question.

British Dictionary definitions for caltrop


caltrap calthrop (ˈkælθrəp)

/ (ˈkæltrəp) /


any tropical or subtropical plant of the zygophyllaceous genera Tribulus and Kallstroemia that have spiny burs or bracts
water caltrop another name for water chestnut (def. 1)
another name for the star thistle
military a four-spiked iron ball or four joined spikes laid upon the ground as a device to lame cavalry horses, puncture tyres, etc

Word Origin for caltrop

Old English calcatrippe (the plant), from Medieval Latin calcatrippa, probably from Latin calx heel + trippa trap 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012