釘

nail / to follow closely / to keep at sb (to do sth) / variant of 盯[ding1]

to join things together by fixing them in place at one or more points / to nail / to pin / to staple / to sew on

male adult / the 4th of the 10 Heavenly Stems 天干[tian1 gan1] / fourth (used like "4" or "D") / small cube of meat or vegetable / (literary) to encounter / (archaic) ancient Chinese compass point: 195° / (chemistry) butyl

surname Jin / surname Kim (Korean) / Jurchen Jin dynasty (1115-1234)

gold / chemical element Au / generic term for lustrous and ductile metals / money / golden / highly respected / one of the eight categories of ancient musical instruments 八音[ba1 yin1]

a thorn in one's side

that clinches it / that's final / no two ways about it

thumbtack

screw

lit. to chop the nail and slice the iron (idiom) / fig. resolute and decisive / unhesitating / categorical

to meet with a rebuff

thumbtack

to make doubly sure (idiom)

The Nine-Toothed Rake (weapon of Zhu Bajie 豬八戒|猪八戒[Zhu1 Ba1 jie4])

peg

a "screw that never rusts" — sb who selflessly and wholeheartedly serves the Communist Party, like Lei Feng 雷鋒|雷锋[Lei2 Feng1], to whom the metaphor is attributed

a thorn in one's side

button magnet (to use on whiteboards, refrigerator doors etc)

stud earring

tongue ring / tongue piercing

hexagon socket head cap screw

tack / thumbtack / push pin

nail gun / stud gun

cramp

claw hammer