Meaning
To improve one’s behavior or performance to an acceptable standard, or else leave a job, team, or organization.
It’s a blunt ultimatum, usually delivered by someone in authority who has already given the person previous chances or warnings.
Origin
The phrase is generally traced to American military slang around the Second World War, where a serviceman who couldn’t meet basic standards of discipline and conduct (“shape up”) faced being reassigned or discharged (“ship out”), literally put on a ship away from his current post or out of service. The rhyme between “shape” and “ship” made the phrase memorable and easy to repeat as a stock warning, and it moved into general civilian English by the 1950s, kept largely intact even as its use spread well beyond any literal military or naval context into workplaces, schools, and sports teams.
Examples
The coach told him to shape up or ship out after he missed another practice.
Management made it clear: shape up or ship out.
After three warnings, it’s shape up or ship out for him.
A: Is he still late every day? B: The boss finally told him shape up or ship out.
Frequently asked questions
What does 'Shape up or ship out' mean?
To improve one’s behavior or performance to an acceptable standard, or else leave a job, team, or organization.
It’s a blunt ultimatum, usually delivered by someone in authority who has already given the person previous chances or warnings.