The term 'Guitar Support' refers to two items that are used to support a guitar while playing. The first item is a KNEE, which is a padded cushion that the guitarist places between their leg and the guitar body. The second item is a STRAP, which is a length of material that is attached to the guitar and worn around the neck or shoulder of the guitarist. Both of these items help to keep the guitar in place while playing and reduce strain on the guitarist's body.