tampion

noun

tam·​pi·​on ˈtam-pē-ən  ˈtäm- 

variants or less commonly tompion

ˈtäm-pē-ən 

: a wooden plug or a metal or canvas cover for the muzzle of a gun

Word History

Etymology

obsolete tampion, tampin plug — more at tamp

First Known Use

circa 1625, in the meaning defined above