noun
serious criminal; heinous criminal
Refers to a person who has committed a grave crime; carries a strong condemnatory tone.
彼は大罪人として歴史に名を残した。
He went down in history as a heinous criminal.
その大罪人は終身刑を
The serious criminal was sentenced to life imprisonment.
重罪犯 is a legal term for 'felon', whereas 大罪人 is more literary and carries a moral condemnation.
Compound of 大 (great) + 罪人 (criminal). The reading だいざいにん follows standard on'yomi.