advb. phr. [Fr.; au at the, to the, fait fact, point, question, under discussion.] In phr. To be au fait in or at: to be well instructed or ‘up to the mark’ in, thoroughly conversant with, expert or skilful in. To put a person au fait of (= F. mettre au fait de): to instruct thoroughly in.
1748. H. Walpole, Lett. H. Mann, II. 255. Being au fait he went up to him at Ranelagh and apostrophized him.
1828. A. Granville, Autobiog., II. 286. I … will put you au fait of all the circumstances of the case.
1859. De Quincey, Incognito, Wks. XI. 11. The gallant troops were not quite au fait in the art of loading.
1881. Daily News, 7 March, 2/3. (Boat-race), Not quite so au fait at the work as Mr. West.
