[kal-truh p]


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.

Also cal·throp [kal-thruh p] /ˈkæl θrəp/, cal·trap.

Origin of caltrop

before 1000; Middle English calketrappe, Old English calcatrippe, colte-træppe, equivalent to calce- (< Latin calci-, stem of calx spur, heel) + træppe trap1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for calthrop

Historical Examples of calthrop

  • Later he goes to see Mr. Calthrop, and wears his white suit with silver lace, having left off his great skirt-coat.

    English Costume

    Dion Clayton Calthrop

  • The Maid, however, had been wounded in the foot by a calthrop, and was besides mortally weary.

    Joan of Arc

    Laura E. Richards

  • Calthrop rode, & likewise of the Gresholme, whereof I find this short description.

  • Outside his own immediate circle Mr. Calthrop has laboured with much effect.

  • The North of London is favoured as regards clergymen, and Mr. Calthrop is a favourable specimen of his class.

British Dictionary definitions for calthrop


caltrap calthrop (ˈkælθrəp)


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