The word "豪宅" is formed by combining the character "豪" (háo), which conveys meanings such as luxurious, grand, or extravagant, with the character "宅" (zhái), which means residence or house. In this compound, "豪" acts as a modifier that describes the type of "宅", resulting in a literal meaning of "luxurious residence" or "mansion". The formation is a direct semantic combination where the descriptive character precedes and qualifies the core noun.