cal.trop \'kal-tr<e>p, 'k<o.>l-\also cal.throp \-thr<e>p\ n (bef. 12c)
[ME calketrappe star thistle, fr. OE calcatrippe, fr. ML calcatrippa]
1a pl but sing or pl in constr: STAR THISTLE 1
1b: PUNCTURE VINE; also: any of various related herbs (genera Tribulus
and Kallstroemia)
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 hoofs
of horses or to pneumatic tires