caltrop (redirected from Star nail)

cal·trop  (kltrp, kôl-)

n.

1. Any of various plants of the genera Tribulus and Kallstroemia, having spiny or tuberculate fruits.

2. A Mediterranean species of star thistle (Centaurea calcitrapa) naturalized in North America.

3. See water chestnut.

4. A metal device with four projecting spikes so arranged that when three of the spikes are on the ground, the fourth points upward, used as a hazard to pneumatic tires or to the hooves of horses.

---

[Middle English calketrappe, from Norman French and from Old English calcatrippe, thistle, both from Medieval Latin calcatrippa, thistle : possibly from Latin calcre, to tread on; see calque + trappa, trap (of Germanic origin).]

---

caltrop, caltrap [ˈkæltrəp], calthrop [ˈkælθrəp]

n

1. (Life Sciences & Allied Applications / Plants) any tropical or subtropical plant of the zygophyllaceous genera Tribulus and Kallstroemia that have spiny burs or bracts

(Life Sciences & Allied Applications / Plants)

water caltrop another name for water chestnut [1]

3. (Life Sciences & Allied Applications / Plants) another name for the star thistle

4. (Military) Military a four-spiked iron ball or four joined spikes laid upon the ground as a device to lame cavalry horses, puncture tyres, etc.

[Old English calcatrippe (the plant), from Medieval Latin calcatrippa, probably from Latin calx heel + trippa trap¹]

Thesaurus

Noun	1.	caltrop - tropical annual procumbent poisonous subshrub having fruit that splits into five spiny nutlets; serious pasture weed devil's weed, Tribulus terestris genus Tribulus, Tribulus - annual or perennial herbs or subshrubs of warm regions subshrub, suffrutex - low-growing woody shrub or perennial with woody base
	2.	caltrop - a plant of the genus Trapa bearing spiny four-pronged edible nutlike fruits water chestnut, water chestnut plant genus Trapa, Trapa - small genus of Eurasian aquatic perennial herbs: water chestnut Jesuits' nut, Trapa natans, water caltrop - a variety of water chestnut ling, ling ko, Trapa bicornis - water chestnut whose spiny fruit has two rather than 4 prongs aquatic plant, hydrophyte, hydrophytic plant, water plant - a plant that grows partly or wholly in water whether rooted in the mud, as a lotus, or floating without anchorage, as the water hyacinth
	3.	caltrop - Mediterranean annual or biennial herb having pinkish to purple flowers surrounded by spine-tipped scales; naturalized in America Centauria calcitrapa, star-thistle centaury - any plant of the genus Centaurea