Caltrop

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Caltrop \Cal"trop\, Caltrap \Cal"trap\, n. [OE. calketrappe,
     calletrappe, caltor (in both senses), fr. AS. collr[ae]ppe,
     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}.]


     1. (Bot.) A genus of herbaceous plants ({Tribulus}) of the
        order {Zygophylle[ae]}, 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]
  
     2. (Mil.) 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]

From WordNet (r) 2.0 [wn]:

  caltrop
       n 1: tropical annual procumbent poisonous subshrub having fruit
            that splits into five spiny nutlets; serious pasture
            weed [syn: {devil's weed}, {Tribulus terestris}]
       2: a plant of the genus Trapa bearing spiny four-pronged edible
          nutlike fruits [syn: {water chestnut}, {water chestnut
          plant}]
       3: Mediterranean annual or biennial herb having pinkish to
          purple flowers surrounded by spine-tipped scales;
          naturalized in America [syn: {star-thistle}, {Centauria
          calcitrapa}]