Definitions

1. adjective

not rifled, especially of a gun barrel; not having grooves cut into its interior surface

“The rifled musket was replaced by the unrifled musket in the new army’s standard issue.”

2. noun

a gun barrel that is not rifled

“The soldier carried an unrifled musket during the battle.”

3. verb

to remove rifling from (a gun barrel)

“The gunsmith unrifled the barrel to convert it into a smoothbore.”