noun
Chinese traitor; Chinese collaborator with the Japanese
Historical term used primarily during the Second Sino-Japanese War for Chinese who collaborated with the Japanese. Strongly pejorative.
戦時中、漢奸と見なされた者は厳しく罰せられた。
During the war, those regarded as Chinese traitors were severely punished.
彼は漢奸として歴史に名を残した。
He went down in history as a Chinese collaborator.
売国奴 is a general term for a traitor to one's own country, while 漢奸 specifically refers to a Chinese traitor, especially one who collaborated with Japan.
From Chinese 漢奸 (hànjiān), literally 'Han traitor'. The term was adopted into Japanese with the same meaning.