Other forms: firearms
A firearm is a weapon that shoots bullets. Rifle, shotgun, pistol — the word covers them all.
It is the formal and legal term, which is why firearms licence, firearms officer and firearms offence are the wordings used in law and in police reports, where gun would be too loose. Britain has among the tightest firearms laws in the world, tightened again after Hungerford and Dunblane. The word is written as one word and is almost always used in the plural in official phrases.
1nounfirearmA portable weapon that fires bullets.
“He was arrested for possession of a firearm.”
From fire + arm.
Etymology from Wiktionary, CC BY-SA