It means uncle, although in anime character regularly use it in its less formal form where it functions more as "mister" or "sir." It's just an informal, but not necessarily rude, way to refer to an older man than yourself that you're unfamiliar with.
That's all I wanted to get clear. Most definitions stop at uncle and barely explain the secondary, and probably more common, use for it. "Ojisan" always means "sir/mister" unless they're actually they're uncle.
A nigerian lady very smart and classy can be very savage but very nice at the same time she is crazy and fun to be with she is loved due to her charisma and her love for others she's very passionate about things she loves and get very excited about things.