All US Marines have been armed with a rifle and bayonet at one time. Some of us have been on the battlefield waiting to hear the word, "Fix bayonets!'' - "Let's go!" as we moved out on the attack. At one time I could not fix bayonets since I was armed with a (BAR) Browning Automatic Rifle, but I kept running forward on the attack.
A bayonet is a knife- or dagger-shaped weapon designed to fit on or over the muzzle of a rifle or similar weapon. It is a close combat weapon.