The characters 朋 and 友 combine to form the modern word 朋友 (péngyou), which means “friend.” Adding 女 (nǚ) at the beginning specifies the gender, but culturally shifts the meaning from platonic to romantic, creating 女朋友 (nǚpéngyou), or “girlfriend.”
In Chinese culture, relationships are often viewed with a greater degree of seriousness and with an eye toward the future. The term 女朋友 (nǚpéngyou) reflects this. Compared to Western dating culture, where “girlfriend” can describe a relationship that is casual or has only been going on for a few weeks, introducing someone as your 女朋友 in China often implies a significant level of commitment. It suggests the relationship is stable, exclusive, and potentially on the path toward marriage. Because of this, announcing you have a 女朋友 to family, especially to parents or grandparents, is a significant event. It will likely be met with many questions about her background, her family, and your future plans together. It's a step up from “just dating” and signals that you are in a serious partnership. Using this term carries the cultural weight of family expectations and long-term commitment.
女朋友 (nǚpéngyou) is a standard, neutral term used across all social contexts, from very casual to relatively formal.