noun
renegade; rebellious elements
Refers to individuals or groups within an organization who oppose authority or the established order, often with a nuance of betrayal.
党内の反逆分子が公然と党首を批判した。
Renegades within the party openly criticized the party leader.
軍の反逆分子がクーデターを企てた。
Rebellious elements in the military plotted a coup.
Compound of 反逆 (rebellion, treason) and 分子 (element, member). The exact historical derivation is uncertain, but the word follows a common pattern for describing subversive members of a group.