Moody這個姓起源自13世紀的愛爾蘭，英美的詞典對於這個姓是這般描述的。
Moody: A family name. Nickname for a courageous, arrogant, or foolhardy person, or one quickly moved to anger, from Middle English modie ‘impetuous’, ‘haughty’, ‘angry’ (Old English mōdig ‘brave’, ‘proud’, from mōd ‘spirit’, ‘mind’, ‘courage’). This English name has been established in Ireland since the late 13th century
牛津大學出版社專門出版過壹本《A dictionary of first names》的工具書，是列舉全部“名”的字典，當中找不到Moody.