lack of virtue; immorality; vice; depravity; unworthiness
Refers to a deficiency in moral character or conduct. Often used in formal or literary contexts to describe personal failing or ethical shortcoming.
It is a result brought about by his lack of virtue.
The politician's immorality is being criticized.
He was deeply ashamed of his own moral failings.
背徳 implies a betrayal of moral standards (often with a sense of transgression), while 不徳 simply denotes a lack of virtue without that connotation of betrayal.
徳 means virtue or moral excellence, the direct opposite of 不徳's lack of virtue.
Sino-Japanese compound of 不 (fu, 'not') and 徳 (toku, 'virtue'). The meaning is transparently derived from its components.