"Lipo" means fat "Stimulin" an agent to stimulate production of ...... ( or an agent that acts upon another to encourage it to produce or release a substance) In Endocrinology, there are many hormones which act upon organs to tell the organs to produce or release certain other substances. "lipostimulin" is a protein This protein can act on other organs to stiumlate synthesis of fat Therefore, "Lipostimulin" is a substance that stimulates the production of specific fat