What it means
A trial go at something before it actually counts. You do a dry run to catch the daft errors, check the timing, and make sure everyone knows what they’re doing without the pressure of a real audience or real consequences. Works for presentations, emergency drills, big events, even packing the car for a trip. Way better to wobble now than implode later.
Usage examples
"We did a dry run of the pitch in the office kitchen, fluffed the slides, reset, and walked into the real meeting calm as you like."
"Let's do a dry run of the presentation before the clients arrive tomorrow."
"The team did a full dry run of the evacuation so nobody panics on the day."
"We did a dry run of the wedding speeches in the living room and thank God, because Uncle Ray's mic technique was pure chaos."
"Let's do a dry run of the school pickup route tonight so we're not freestyling the madness at 8 a.m."
Where it comes from
This one really does come from firefighting and other technical drills, where a run was done without using the live stuff, especially water. From there it spread into everyday English for any practice go that lets you catch the stupid bits before the real thing starts breathing down your neck.
