What is a Dry Run?

Dry Run Meaning

Definition: A rehearsal or practice before the actual event.

Origin of Dry Run

The origin of this expression is unclear. Most sources show that this idiom started becoming popular in the 1900s.

The military frequently used this idiom in the early-20th century, leading us to our first origin story.

Some sources say this expression originated during World War 2, where it was used to describe practice bombing flights where no actual bombs were dropped.

Similarly, if soldiers were doing a practice drill without ammunition, this was a dry run. Many sources speculate that dry meant without bullets or bombs and run meant practice, and that the idiom became generalized from this initial source.

Other sources state that another explanation comes from firefighters doing practice drills without water. The use of the word dry here would make more literal sense.

A third possibility comes from geography. Many dried up old riverbeds had the name dry run. The military often held practice drills in these areas because it provided realistic cover for the types of areas the soldiers would fight in. This would explain both the word dry (no water) and run (river). As another point in favor of this explanation, the earliest examples of the expression dry run in the digital records are all for dried up rivers.

However, there is no evidence strong enough to prove one of these origins over the other.

Examples of Dry Run

dry run definitionIn this example, two sisters are preparing for Black Friday.

Amy: I’m not sure we are physically and mentally prepared for all the stress that comes with trying to get the best deals on Black Friday.

Kimberly: You’re right. Maybe we should do a dry run the day before Thanksgiving. That way we’ll know the layout of the store well and can maneuver quickly on the actual day.

Amy: Okay. Good idea.

define dry runIn the second example, two friends are relaxing at the beach.

Keira: I really want to learn to surf, but I’m scared to try.

Rory: You should try! It’s fun. We’ll do a dry run first by practicing on the sand.

More Examples

This excerpt is from an article about the World Series and how it affects the local area.

  • The party, however, will spill well outside Minute Maid, with big crowds expected at nearby bars and restaurants, some of which got a dry run for the World Series with two league championship-clinching games in the past week. –Houston Chronicle

This excerpt is about the founder of Facebook who is feeling out running for president.

  • This Thursday, as bad press and political pressure built up, the tech giant rolled out a P.R. push that was half crisis management and half 2020 presidential dry run for 33-year-old CEO Mark Zuckerberg, who became the world’s fifth richest person by “moving fast and breaking things” and now natters on about “giving people the power to build community.” –New York Daily News


The saying dry run means practice through a simulation of the real event.