A serious relationship refers to a committed, long-term romantic partnership between two individuals. It implies that both parties are deeply invested in each other emotionally and often physically as well. In such a relationship, there is usually an expectation of exclusivity, loyalty, and commitment from both people involved. This type of relationship typically involves mutual support, trust, and respect for one another's feelings, goals, and boundaries. The term "serious" in this context implies that the individuals are fully invested in building a strong bond with each other and working towards a common goal of creating a stable and fulfilling partnership.