Trooper-Trouper | Commonly Confused Words

Trooper

/ˈtruːpə/

A soldier, especially one who belongs to a group like cavalry or airborne units

The trooper saluted as the commander passed by.She's a real trooper, working late into the night.The film's hero was a brave space trooper.

/ˈtruːpə/

A person who is reliable, resilient, and performs well under pressure, especially in a group setting.

She handled the crisis like a real trouper.Despite setbacks, she remained a committed trouper.The kids were real troupers during the long road trip.

Think of trooper like a soldier who is part of a troop. They troop around doing brave and disciplined activities.
Trouper relates to performers and the phrase the show must go on—they persevere no matter what.
Remember, trouper has u as in troupe, which means a group of entertainers.
Both trooper and trouper suggest resilience, but in different fields: military vs entertainment.
An easy mnemonic is Troupers in a troupe, Troopers in a troop.