Au fait and At home

Au fait adjective - Being up to particular standard or level especially in being up to date in knowledge.

At home and au fait are semantically related. in familiar topic. In some cases you can use "At home" instead an adjective phrase "Au fait".

At home adverb - At, to, or toward the place where you reside.

Au fait and at home are semantically related. Sometimes you can use "Au fait" instead an adjective phrase "At home".