棘 - thorn, splinter, spine

echinoderm

briars; thicket; the bush

wild rose; bramble

acanthodians (extinct jawed fishes)

spinous process

Muennink's spiny rat (Tokudaia muenninki); Okinawa spinous country-rat

sand sifting starfish (Astropecten polyacanthus); comb star

infraspinatus muscle

flat rock crab (Percnon planissimum)

helmet crab (Telmessus acutidens)

stickleback (Gasterosteidae spp.)

there is no rose without a thorn; every rose has its thorn