1) Artillery component 2) Kind of firearm 3) Not rifled 4) Of a firearm 5) Type of Artillery 6) Unrifled 7) Unrifled arm 1) Unrifled 
A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. The majority of shotguns are smoothbores and the term can be synonymous. ==History of firearms and rifling== Early firearms had smooth barrels, and fired projectiles with no significant spin. Th...
• (n.) A smoothbore firearm. • (a.) Having a bore of perfectly smooth surface; -- distinguished from rifled.
Smooth'bore` adjective (Gun.) Having a bore of perfectly smooth surface; -- distinguished from rifled . -- noun A smoothbore firearm. 
noun a firearm that has no rifling