A compound which is made by the body and is used to store energy in the form of phosphate molecules. When phosphate molecules are attached to it, it is called creatine phosphate and is capable of donating phosphate to ADP in order to make ATP. (ATP is the molecule which is converted into ADP with a release of energy that the body is then able to use.)

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.