What does 'fluent' mean?

Would I ever be able to speak Chinese fluently, and what would that mean? I had reached a stage where I was starting to speak more coherently, but on some days it felt like I was not able to speak at all. Crucially, my speaking lagged well behind my understanding and I would often have to stop to search for words when speaking. What level was I at now? Could I use descriptors for language proficiency to identify my current level of Chinese?