Bay·o·net n.
 1. Mil. 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 offense and defense.
 Note: ☞ Originally, the bayonet was made with a handle, which required to be fitted into the bore of the musket after the soldier had fired.
 2. Mach. A pin which plays in and out of holes made to receive it, and which thus serves to engage or disengage parts of the machinery.
 Bayonet clutch. See Clutch.
 Bayonet joint, a form of coupling similar to that by which a bayonet is fixed on the barrel of a musket.
 bayonet mount, photography a coupling mechanism for attaching removable lenses to the body of a camera, using a bayonet socket.
 bayonet socket, a coupling mechanism for attaching matching cylindrical parts to each other, where each of which has an arced L-shaped slot with the longer side perpendicular to the axis of the cylinder, such that the slots slide inside each other.  There is also  usually a knoblike projection on the mount so that when the two parts to be connected are fully inserted in proper alignment, they are locked in place.  It is designed for rapid coupling and decoupling, requiring the turning of one part through only a small arc, in place of a screw-type arrangement, which requires several full turns.