Dictionary / Vocabulary / もの知らず
ものしらず
stupidity; ignorance; stupid person; ignorant person
Also written 物知らず、物識らず、モノ知らず、物しらず
恐いもの知らずのその男は憎しみと軽蔑の目でやくざをちらりと見た。
The bold man glanced at the gangster with hatred and contempt.