A cushion-like device that reduces shock due to an impact WordNet 3.0 & Open English WordNet

In boating, a fender is an air-filled ball or a device in other shape and material used to absorb the kinetic energy of a boat or vessel berthing against a jetty, quay wall or other vessel. Wikipedia

A bumper used to keep boats from banging into docks or each other Wikipedia Disambiguation

Element protecting the hull of a ship Wikidata

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. Wiktionary