Gaff and boom are two pieces of equipment used in sailing. A gaff is a spar that holds the upper edge of a fore-and-aft sail, while a boom is a spar that holds the lower edge of the sail. The term 'gaff and boom' is often used to refer to the entire assembly of SPARS, sails, and rigging used to control a sailboat. The crossword solution for this term is SPARS, which stands for 'Sailboat Parts Assembly Rigging System'.