Refers to the third molar, typically emerging in late teens or early adulthood. Often used in medical or everyday contexts.
My wisdom tooth hurt, so I went to the dentist.
親知らずを抜く手術を受けた。
I had surgery to remove my wisdom tooth.
not knowing one's birth parents; person who does not know their birth parents
Literally 'not knowing one's parents'. Can refer to the state of being unaware of one's biological parents, or a person in that situation. Often used in discussions of adoption or orphanhood.
彼は親知らずで育った。
He grew up not knowing his birth parents.
親知らずの子供たちを支援する団体がある。
There is an organization that supports children who do not know their birth parents.