noun, noun or participle which takes 'suru'
Specifically refers to romantic or marital faithfulness; staying true to one's partner.
彼女は夫に心中立てを尽くした。
She remained completely faithful to her husband.
心中立てを誓
To vow fidelity.
noun, noun or participle which takes 'suru'
Broader loyalty beyond romance, such as to a lord, master, or cause. Somewhat literary or old-fashioned.
主君への心中立てを貫いた。
He remained loyal to his lord.