叛

Formed as a phono-semantic compound:

反 (“to turn back, oppose”) provides the semantic element, indicating reversal or turning away.

半 (“half”) provides the phonetic element.

Together, they express the sense of turning against one’s side or splitting away.

Semantic range:

- to betray, to turn traitor (배반하다);

- to revolt, to rebel (반란하다);

- by extension: to desert, to defect.

배반 (背叛) — betrayal, treachery

반역 (叛逆) — rebellion, insurrection

반도 (叛徒) — traitor, rebel

반심 (叛心) — rebellious intent, disloyal heart

叛 is strongly tied to Confucian political ethics, where loyalty (忠) to ruler, parents, and state was paramount. To commit 叛 was among the gravest offenses, disrupting the moral order. In imperial law codes, terms like 叛逆 (“rebellion”) or 背叛 (“betrayal”) carried the heaviest punishments.

The word’s gravity persists in modern Korean, Chinese, and Japanese, where it still conveys not only “betrayal” but also a profound moral breach.