The Proto-Turkic word *kök
Word *kök
Meaning hinge, nail
See also Proto-Altaic: *kʰōki ‘hinge, hook’
Proto-Tungus: *siaKu- ‘loop, hinge’

Other words that might be of interest
*eg- ‘to bend’, *kiān ‘blood’, *siŋök ‘bone’, *kak- ‘to hit, knock, tear’, *sɨ̅- ‘to break, damage, harm, to be broken’, *üŕ- ‘to break, tear, demolish’, *dö̅ĺ ‘breast’, *emig, emček ‘breast, nipple, to suck’, *göküŕ / gögüŕ, kökrek ‘breast’, *dɨrŋa-k ‘fingernail, claw’, *bɨč / bič ‘to cut’, *jār- ‘to split, split, crack’, *jī́r- / jɨ̅r- ‘to split lengthwise, to break, tear’, *kes- ‘to cut’, *kɨr- ‘to break, scrape, shave’, *sök- ‘to split, tear apart’, *īĺč ‘work, deed’, *kɨl- ‘to do, make’, *kul-kak ‘ear’, *jumurtka ‘egg’, *ark ‘excrement’, *köŋ ‘excrement, faeces’, *gör- ‘eye, to see, look’, *karak ‘eye, eyeball’, *jüg ‘feather’, *biarŋak ‘finger, thumb’, *adak ‘foot’, *būt ‘thigh, leg, foot’, *āl ‘front, forehead, in front of’, *kɨl(k) ‘hair’, *s(i)ač ‘hair’, *tǖk ‘hair, feather, fur’, *el(ig) ‘hand’, *kar ‘arm, forearm, various measures of length’, *kol ‘arm, hand’, *baĺč ‘head’, *göjŋ-il ‘heart, mood’, *jürek ‘heart’, *sok- ‘to hit, beat, crush’, *tokɨ- ‘to hit, knock, strike, mallet’, *bujŋuŕ / büjŋüŕ ‘horn’, *dīŕ ‘knee’, *erin ‘lip’, *burun / burɨn ‘nose’, *k(i)aŋ(ɨr)- ‘nose’, *dẹri ‘skin’, *jạt- ‘to lie, sleep’, ‘sleep’, *ū-dɨ- ‘to sleep’, *kudruk ‘tail’, *dɨl / dil ‘tongue’, *jālga- ‘to lick’, *dāla- ‘to bite’, *dīĺ ‘tooth’, *ɨsɨr- ‘to bite’, *kājnat ‘wing’, *kır- ‘to break, to split’, *gēp ‘form, example, image’, *kaŋïr ‘to bend’