abettor, activator, actuator, animator, arouser, cajoler, coax, coaxer, encourager, firer, gadfly, galvanizer, human dynamo, impeller, inducer, inspirer, life, motivating force, motive power, mover, moving spirit, persuader, pleader, prime mover, prompter, restorative, spark, spark plug, sparker, stimulant, stimulator, stimulus, tempter, tonic, wheedler