It has more than one meaning. She is a tall,fair haired lady. She has light/blonde hair. She is a fair lady. She is reasonable, right and just. For daily usage you could say "fair enough" in a situation where someone says something that is reasonable and you respond "fair enough". For a more in depth explanation Collins dictionary explains it nicely: fair enough PHRASE You use fair enough when you want to say that a statement, decision, or action seems reasonable to a certain extent, but that perhaps there is more to be said or done. [mainly spoken] If you don't like it, fair enough, but that's hardly a justification to attack the whole thing. Fair enough, you didn't have a perfectly happy childhood: but your childhood is over now.

Fair means pretty or beautiful in the first example. In the second example 'fair enough' means its ok for me or your argument seems acceptable.

A: I'd love to come to your party but I've got my final exams next week and I really need to stay at home and study, or I'm going to fail! B: Yup, fair enough. Good luck with your exams. There's always next time. Without any further context, I understand "fair lady" to mean attractive woman.

In that set expression, "fair" means beautiful and refined. I've often seen "fair lady" translated into Chinese as Shūnǚ.

The “fair”in “fair lady” means to be beautiful. “Fair enough” is a common use in daily life which refers to be reasonable, right and just.