| accelerator(noun, substance, agent, chemical) |
| incentive(noun, activity, charge, drive, cause) |
| impetus(noun, activity, force, charge, drive) |
| agitator(noun, activity, spur, goad, incentive) |
| stimulus(noun, charge, drive, cause, drug) |
| impulse(noun, activity, charge, drive, cause) |
| spur(noun, activity, charge, feeling, drive) |
| agent(noun, desire, urge, spur, lure) |
| stimulant(noun, activity, charge, cause, drug) |
| motivation(noun, activity, charge, feeling, drive) |
| catalyser(noun, agent, chemistry, fuel) |
| catalytic agent(noun, expression, substance, agent, chemical) |
| cause(noun, charge, boost, spur, stimulus) |
| enzyme(noun, activity, substance, spur, goad) |
| reactionary(noun, activity, spur, goad, incentive) |
| biocatalyst(noun, substance, agent, chemical) |
| incendiary(noun, activity, spur, goad, incentive) |
| energy(noun, power, agent, thrust, motive) |
| mover(noun, desire, urge, spur, leader) |
| goad(noun, activity, charge, feeling, drive) |