Mammy/ˈmæmi/ Definition 1 of 2Pro Tip 1/3Regional Usage Mainly used in Ireland and the Southern United States, less common elsewhere. Did you hear Jamie talking about his mammy? He must be from the South. Pro Tip 2/3Affectionate Tone Conveys warmth and closeness when referring to one's mother. My mammy always knows how to make me feel better. Pro Tip 3/3Not Formal Inappropriate for formal contexts; use 'mother' instead. You wouldn't say 'Let me introduce you to my mammy' at a formal event.