caltrops
Scattered tire puncturers
Caltrops are spiked metal devices scattered on the ground to puncture tires or injure feet and hooves.
The classic design has four points arranged so one always faces upward.
Ancient armies used them against cavalry; modern versions disable vehicles.
The word also names a plant with spiny seed pods that work the same way: I got caltrops stuck in my bike tire.
Of ancient Italy's capital
- legionGreat number, or soldiers
- chariotAncient horse-drawn fighter's vehicle
- siegeEncirclement forcing surrender
- battlegroundLocation of armed combat
warfare · infantry · cavalry · phalanx · hoplite · fortification · ambush · catapult
Sharp rise or point
- prongPointed projecting part
- tetrahedralHaving four triangular sides
- pointedTapering to a tip
- metalHard conductive solid
iron · steel · scattered · thrown · concealed · ground · puncture · tire
Shape's outer edge length
- deterrentThing that discourages action
- strategicDeliberately planned for advantage
- anti-personnelDesigned to injure humans
- roadblockObstruction across a road
checkpoint · barricade · fortification · security · protection · barrier · entrenchment · denial
Civil law enforcement
- pursuitAct of chasing something
- vehicleMeans of transport
- roadVehicle travel surface
- deploymentOrganized distribution of resources
strip · puncture · law enforcement · military · checkpoint · protest · sabotage · improvised
Edible aquatic corm
- bullheadBroad-headed freshwater fish
- seedsPlant embryos in casings
- spinyHaving sharp points
- invasiveEncroaching without welcome
weed · thorny · burr · painful · sandal · bicycle tire · naturalized · Mediterranean
Roman
Of ancient Italy's capital
- legionGreat number, or soldiers
- chariotAncient horse-drawn fighter's vehicle
- siegeEncirclement forcing surrender
battleground · warfare · infantry · cavalry · phalanx · hoplite · fortification · ambush · catapult · ballista
spike
Sharp rise or point
- prongPointed projecting part
- tetrahedralHaving four triangular sides
- pointedTapering to a tip
metal · iron · steel · scattered · thrown · concealed · ground · puncture · tire · hoof
perimeter
Shape's outer edge length
- deterrentThing that discourages action
- strategicDeliberately planned for advantage
- anti-personnelDesigned to injure humans
roadblock · checkpoint · barricade · fortification · security · protection · barrier · entrenchment · denial · chokepoint
police
Civil law enforcement
deployment · strip · puncture · law enforcement · military · checkpoint · protest · sabotage · improvised · DIY
water chestnut
Edible aquatic corm
invasive · weed · thorny · burr · painful · sandal · bicycle tire · naturalized · Mediterranean · tropical
- Ninjaninja, shinobi, kunoichi, ninjutsu, shuriken
- trapstrap, bear trap, mousetrap, rat trap, ant trap
- Roman militarylegion, cohort, centurion, legionnaire, legionaries
- martial weaponskatana, nunchaku, shuriken, bo staff, sai
- fortificationsfort, fortress, fortresses, citadel, citadels
- ancient projectilesarrow, bolt, javelin, spear, crossbow bolt
caltropsroad
Vehicle travel surface
bridge · pathway · ramp · welcome mat · red carpet
caltropswelcome sign
Display announcing friendly reception
safe passage · invitation · access ramp · entryway · open door
caltropsminesweeper
Vessel clearing sea explosives
road grader · demining · smoothing · paving · grading