look up any word, like bae:
 
1.
A shirt that is specifically worn when there is a risk of food landing on it.

Generally characterized by being old, pit stained, with bonus points awarded for rips or tears.
Spaghetti tonight dear? I best be putting on my napkin shirt.

and

Eww - I can't believe you wore that napkin shirt to dinner with my parents!
by jiggerbigger001 April 23, 2010