sleevelet
/ˈslɛvlet/ or /ˈslɛvliːt/Definitions
1. noun
A small sleeve or a sleeve-like part, especially one that can be folded back or detached.
“The designer added a sleevelet to the collar of the shirt for extra style.”
2. verb
To provide with a small sleeve or sleeve-like part.
“The seamstress sleeveleted the jacket to make it more comfortable.”