The term UNIT FUSE is a combination of two words, AMP and FUSE. An AMP is an abbreviation for ampere, which is a unit of electrical current. A FUSE is a safety device that is used to protect electrical circuits from overloads. When too much current passes through the circuit, the FUSE will blow, cutting off the power and preventing damage to the circuit. The combination of an AMP and a FUSE is used to protect electrical circuits from overloading and potential damage.