For fair

For fair. I heard this many times from older people but have no idea what it really means. anybody have the answer

I believe it means somewhat the same thing as “for certain”.

Did you hear this in the US, Canada, Britain or somewhere else? I have never heard this term used by anyone anywhere or seen it in TV or film.

Or maybe they are making some marmalade for the State Fair. “These oranges are for Fair.”

State Fair was also a fun old movie.

According to this, “completely and finally.”

So, probably a clever variation on “for good”…

Quite possibly.
The one time I heard it was from 2 great-uncles. One said " That will settle this problem for good." and the other responded “Well, at least for fair”, indicating some skepticism about this settling of the problem.

Or indicating the same meaning (i.e., completely), but having a little wordplay fun with other meanings of “good” and “fair.”

If there had been a third great-uncle there, he might have continued with “for poor.”