Longman Dictionary of Contemporary English
party piece
noun
EXAMPLES FROM CORPUS
▪ Then came Solano's party piece, and a frantic finish.
▪ Together they revived their party piece from the Sixties, Open Country, which like everything they played, was superb.
Usage examples of "party piece".
It was a sort of joke, I think: his idea of a party piece, never to be the same person twice.
He knew that what Andawyr had just done was little more than a party piece for entertaining children.
Keredin performed what he called his party piece, and orange flames burst from the embers.
As a party piece, on high day feasts, he would crack walnuts between his strong square teeth.
And in view of what you told me of the origin of Ampris's party piece, I eagerly await your critical appraisal.
Every one of them seemed to have a party piece, which the rest would listen to appreciatively and applaud loudly—.