dress rehearsal

plural dress rehearsals

1. entertainmentA rehearsal prior to a public spectacle, where all the performers are in costume, in order to test all aspects of the production by closely reproducing the actual conditions of a performance.

   We've got three dress rehearsals before the opening night to prepare ourselves for any potential technical issues.

2. The final rehearsal before a performance, whether or not costumes or performance dress are worn.
3. broadlyAny complex activity that serves to prepare for a more important iteration of it later.

   Although the train derailment ended up not being very serious, the emergency services' response served as a dress rehearsal in case of a much worse disaster.

   2 more examples

   Sunday, November 6, was spent in a second full-scale dress rehearsal of the complete weekday electric timetable, [...] during which the public were invited to make their first trial of the trains—and 15,000 did so.

   1960 December, “The Glasgow Suburban Electrification is opened”, in Trains Illustrated, page 712

   And if anybody thinks that that was not a dress rehearsal for what they may try to attempt in January of 2025, I’m sorry to say, but I think that’s a very naïve assumption.

   2024 April 12, Shane Goldmacher, quoting Alexandria Ocasio-Cortez, “Ocasio-Cortez Never Steered Money to a Key Arm of Her Party. Until Now.”, in The New York Times