a thorn, prickle, needle / a calling card, name card

sharp / pointed / stab

swordplay, swordfight

a finger

point / finger / to point at / to indicate / to refer to

point (at, to)

stab wound

(emphatic) Synonym of 刺す (sasu)

finish off, deliver the final blow (so to ensure (something) is dead) / (idiomatic) deliver the final blow (so to ensure (someone or something) to have no hope for recovery)

(idiomatic, figuratively) to give a warning, to remind a person of