Related Clues:

• Implied but not spoken
• Mother - she's the word for secrecy
• A continent
• Keep quiet, mother
• Implied or understood, not put into words
• Unable to speak
• Understood but not spoken
• Keep it secret from mother?
• Understood without being put into words
• Listen in order to be quiet
• Not said but understood
• Implied or understood
• Utterly quiet
• Speechless, soundless
• Although quite unsound, this is back, what I loaned