Definition: The word "mortgage nerd" refers to someone who specializes in mortgage lending, or the act of lending money for property purchases, and who has a strong background in understanding and applying financial principles, including mortgages and loans. The term "nerd" is often used as a way to describe individuals who are highly creative, intelligent, and well-read. In this context, a person referred to as a "mortgage nerd" might be someone whose background in finance or mortgage lending has contributed significantly to their knowledge and understanding of the subject matter. In summary, "mortgage nerd" refers to someone who specializes in mortgage lending or loans, and who is knowledgeable about financial principles such as mortgages and loans.