The term 'BOOM SUPPORT' is composed of three words: MAST (4 letters), RAH (3 letters), and SIS (3 letters). MAST stands for a tall vertical structure used to support sails on a sailing vessel, while RAH stands for the exclamation of joy or triumph. Finally, SIS is an informal term for a sister or female sibling. Together, these three words form the phrase 'BOOM SUPPORT, ' which refers to the support provided by a MAST and boom combination, which is used to hold a sail in place.