知らず
1
not having;unaffected by
あいつは馬鹿だから、怖いもの知らずだ。
He is too dumb to fear danger.
2
conjunction
aside;I don't know about ...
often as ～は知らず
3
conjunction
I know not whether;I know not if
at the beginning of a sentence
Other forms
不知 【しらず】