smoothbore
smooth.bore \-'bo-(*)r, -'bo.(*)r\ \'smu:th-.\ aj of a firearm : having a smooth-surfaced bore - smoothbore n
Webster's English Dictionarysmooth.bore \-'bo-(*)r, -'bo.(*)r\ \'smu:th-.\ aj of a firearm : having a smooth-surfaced bore - smoothbore n