The difference between Fender and Mudguard

Fender as a noun (US):

Panel of a car which encloses the wheel area, especially the front wheels.

Fender as a noun (US):

A shield, usually of plastic or metal, on a bicycle that protects the rider from mud or water.

Fender as a noun (nautical):

Any shaped cushion-like object normally made from polymers, rubber or wood that is placed along the sides of a boat to prevent damage when moored alongside another vessel or jetty, or when using a lock, etc. Modern variations are cylindrical although older wooden version and rubbing strips can still be found; old tyres are used as a cheap substitute.

Fender as a noun:

A low metal framework in front of a fireplace, intended to catch hot coals, soot, and ash.

Fender as a verb (nautical):

To use fenders to protect the side of a boat

Mudguard as a noun:

A cover over the wheels of a vehicle, or a flap behind that wheel, to prevent water and mud being projected.