Au fait

Au` fait' (ō` fa'). [ French Lit., to the deed, act, or point. Fait is from Latin factum . See Fact .] Expert; skillful; well instructed.
Found on http://www.encyclo.co.uk/webster/A/144

Au fait

• Expert; skillful; well instructed.
Found on http://thinkexist.com/dictionary/meaning/au_fait/

Au fait

Another one of those French expressions that have slipped into the English language. This one means to be familiar with something. I'd say at the end of reading all this you'd be au fait with the differences between American and English!
Found on http://www.effingpot.com/slang.shtml
No exact match found