忠誠|ちゅうせいchuusei[0]heiban (flat)

1. na-adjective, nounloyalty; sincerity; allegiance; fidelity; integrity
   君きみの忠誠ちゅうせいを当あてにしてもいいかい。↗

   Can I count on your loyalty?

• Synonym忠義ちゅうぎWrittenDevotion to one's lord as a moral duty, with feudal overtones; written register. 「忠誠」 stresses allegiance to a country or organization and can be sworn, as in 「忠誠を誓う」.
• Synonym忠実ちゅうじつNeutralFaithful in carrying out instructions, and also true to an original, as in 「原作に忠実」; broader in use than 「忠誠」.
• Synonym忠節ちゅうせつWrittenLoyalty as unbending integrity — the virtue of holding fast to one's principles; archaic, found in written prose.
• Synonym忠信ちゅうしんWrittenLoyalty coupled with keeping faith; stresses honesty and dependability. Rare even in written prose.
• Synonym誠忠せいちゅうWrittenThe same word as 「忠誠」 with the characters reversed; identical in meaning, rare and confined to written prose.
• Synonym忠心ちゅうしんWrittenA loyal heart; stresses inner, wholehearted devotion. Written style.
• Related忠義立てちゅうぎだてNeutralA loyal act or stance on behalf of one's lord or organization; can hint that the loyalty is being put on display. Neutral in register.
• Related忠順ちゅうじゅんWrittenLoyalty joined to obedience; stresses compliance with superiors' commands. Rare, written style.
• Antonym背信はいしんWrittenBreach of faith and betrayal of trust — the direct opposite of 「忠誠」; seen in 「背信行為」. Written register.
• Antonym反逆はんぎゃくNeutralTreason or rebellion against a ruler or government — the opposite of 「忠誠」; as in 「反逆罪」.

Use 「忠誠」 for allegiance to a country, organization, or leader, as in 「忠誠を誓う」. For devoted service to a lord, say 「忠義」; for faithfully carrying out instructions or staying true to an original, 「忠実」; for a loyal deed, at times put on show, 「忠義立て」. The opposites are 「反逆」 and 「背信」; most other terms are rare written words.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 忠義ちゅうぎを尽つくすこと。