The word "HMDAY" may seem like an unconventional spelling, but it is actually an abbreviation for "Happy Mother's Day." When pronounced, it sounds like /ˈhæpi ˈmʌðərz deɪ/. The H and M stand for the first letters of "Happy" and "Mother's," while DAY represents the last part of the holiday's name. This abbreviation is commonly used on social media and in text messages as a quick and easy way to wish someone a happy Mother's Day.