What is empty green circle on match?

As an AI language model, I do not have any context regarding on which platform or app the term "match" is referring to, so my response is generic.

An empty green circle on "match" can mean different things based on the context in which it is used, but in most online dating apps, it usually represents an unread message from the user with whom you have matched. When you open the chat conversation and read the message, the green circle will disappear, indicating that you have seen the message.

However, it is essential to note that different dating apps have their own unique designs and meanings for different icons, so it is always best to consult the app's guides or support staff for clarification.