(ふたごころ)

ふたごころ
noun
duplicity; treachery; disloyalty
1. duplicity; two-facedness; disloyalty
having hidden intentions or being disloyal to someone while pretending loyalty
二心(ふたごころ)のない人間(にんげん)だ。
He is a person without duplicity.
(かれ)には二心(ふたごころ)があるようだ。
It seems he has hidden intentions.
二心(ふたごころ)(いだ)いて(つか)えることはできない。
One cannot serve with a disloyal heart.

二心(ふたごころ) describes the state of harboring secret intentions while outwardly showing loyalty. It carries a strongly negative connotation of betrayal or disloyalty.

ETYMOLOGY:
From (ふた) (two) + (こころ) (heart/mind), literally "two hearts" — having divided loyalties.

COMMON PATTERNS:

  • 二心(ふたごころ)がない: to be without duplicity, to be sincere
  • 二心(ふたごころ)なく: without reservation, wholeheartedly
  • 二心(ふたごころ)(いだ)く: to harbor disloyalty

REGISTER:
A literary, somewhat old-fashioned word. More commonly encountered in historical dramas, period fiction, and formal contexts than in everyday conversation.

CONTRAST:

  • 一心(いっしん): single-mindedness, wholehearted devotion (opposite meaning)
  • 裏切(うらぎ)り: betrayal, treachery (more common everyday word)
  • 二心(にしん): same kanji but literary on'yomi reading