Mom/mɑːm/ Definition 1 of 2Pro Tip 1/3Informal Term Used casually, especially in American English, to refer to one's mother in everyday conversation. I'm going shopping with my mom later. Pro Tip 2/3Affectionate Address 'Mom' conveys a sense of warmth and affection when addressing your mother directly. Thanks for the advice, Mom. Pro Tip 3/3Personal Connection Using 'mom' suggests a close personal relationship in contrast to 'mother,' which is more formal. My mom knows me better than anyone.