a knife that can be fixed to the end of a rifle and used as a weapon
A pointed instrument of the dagger kind fitted on the muzzle of a musket or rifle, so as to give the soldier increased means of offence and defence. Originally, the bayonet was made with a handle, which needed to be fitted into the bore of the musket after the soldier had fired.
stab or kill someone with a bayonet
To stab with a bayonet.