Borrowed from French au fait (literally “at fact”).
au fait (comparative more au fait, superlative most au fait)
- Being familiar with or informed about something.
- Are you au fait with the rules of the game?
- 1871, Now there is father; he is au fait in all these matters; has a theory for every case of whooping-cough, — and a mission school. — Elizabeth Stuart Phelps in The Silent Partner, collected in Popular American Literature of the 19th Century ISBN 0195141407, p. 857
- 1999, In that case, it would help to have a benevolent deity who is au fait with those complexities — but that there is such a deity is a feature of Stoic theology. — R.J. Hankinson in The Cambridge History of Hellenistic Philosophy, ISBN 0521250285, p. 535
- 2003, This may sound needless to the professional who is au fait with the history and direction of the investigation. — D R J Laming in Understanding Human Motivation: What Makes People Tick? ISBN 0631219838, p.4