彼の奥さんはもとは玄人だったという噂がある。
Rumor has it that his wife used to work in the nightlife trade.
玄人だけあって、彼女は客のあしらいがうまい。
As you would expect of a woman of the trade, she is good at handling customers.
あの着物の着こなしは、どう見ても玄人だ。
From the way she wears that kimono, she is clearly a woman of the entertainment world.