This is the 9143rd most frequent Turkish word.
tüysüz
Hairless or featherless.
Here, 'tüysüz' is used as an adjective to describe the dog, meaning 'hairless' or 'without fur'.
Bu hayvan tüysüz bir köpektir.
This animal is a hairless dog.
In this sentence, 'tüysüz' describes the head of the father, indicating a lack of hair on that part of the head.
Çocuk, babasının tüysüz kalan başına dokundu.
The child touched the hairless part of his father's head.
Here, 'tüysüz' is used metaphorically to describe the smooth surface of a faucet, akin to having no hair-like texture.