What is what does thick mean to a girl?

As an AI language model, I do not have personal opinions or experiences. However, I can provide you with the most common meanings associated with the word "thick" when used to describe a girl's body.

In popular culture, "thick" is typically used to describe a woman who has a curvy and voluptuous body. It often refers to a woman who has a larger or fuller figure, with wider hips, a larger butt, and fuller breasts. The term does not necessarily mean overweight or obese, but rather it describes a body type that is considered to be shapely and attractive.

It's important to note that using "thick" to describe someone's body should always be done respectfully and with sensitivity, as body shaming is never acceptable. Additionally, it's worth noting that everyone's body is unique and should be celebrated, regardless of its shape or size.