I play music at a low level but often get paid reasonably , and by most peoples definition they'd call me a musician for doing so.
I play football at a low level, yet i'm not a footballer
Personally I find the title "musician" a bit silly for someone like me, I can recreate basslines, and hold a band together timing wise, and I have great confidence playing certain genres well, but I don't think I should be called a musician unless I could read sheets and busk along at a much higher level than I currently and ever will do.