Arm support, in particular for a motor vehicle

The armrest (1) has a supporting portion (7) which is arranged around a pivot axis between normal position and pivoted position, on a plastic support (3). A locking unit (12) is provided for locking the supporting portion in pivoted position. The locking unit is provided for defining the pivoted position as reversible ingestible position permanently so that the support portion is moved from pivoted position without changing the predetermined locking position.