peace of mind

Từ điển WordNet v3.1 - WordNet Dictionary

noun

the absence of mental stress or anxiety (Freq. 1)
• Syn:
peace, peacefulness, repose, serenity, heartsease, ataraxis
• Derivationally related forms:
pacify (for: peace)
• Hypernyms:
tranquillity, tranquility, quietness, quietude