Shirt
Shirt turns up in 2 fields: aviation, textiles. Here is what it means to the people in each one.
Shirt in aviation
The informal nickname for a First Sergeant in the United States Air Force.
The Shirt is the senior enlisted advisor to a unit commander, responsible for the morale, welfare, and conduct of all enlisted personnel in that squadron. They handle disciplinary actions, barracks inspections, and personal issues, acting as the primary liaison between the enlisted force and the commanding officer.
"You better make sure your boots are polished before you get called in to see the Shirt."
Shirt in textiles
A tailored garment for the upper body, typically featuring a collar, sleeves, and a front opening.
An upper-body garment constructed from woven fabric, generally characterized by a collar, sleeves with cuffs, and a full vertical opening fastened with buttons. In tailoring and manufacturing, it is distinguished from knit tops like tees or polos by its structured construction and use of woven piece goods.
"The client wants a custom dress shirt with a spread collar and French cuffs."