noun which may take the genitive case particle 'no', noun
ungrateful; unappreciative
Describes a person or attitude that does not show gratitude for kindness or help received. Often used in phrases like 感謝知らずな人 or 感謝知らずの態度.
He is always ungrateful and never says thank you even when someone helps him.
That kind of ungrateful attitude hurts the people around you.
Compound of 感謝 (gratitude) + 知らず (not knowing), literally 'not knowing gratitude'.