| ferment(noun, change, agent, chemistry) |
| accelerant(noun, desire, urge, spur, lure) |
| force(noun, power, push, means, agent) |
| incitation(noun, activity, charge, feeling, drive) |
| incitement(noun, activity, charge, feeling, drive) |
| leaven(noun, change, agent, chemistry) |
| prompting(noun, power, agent, motive) |
| propellant(noun, charge, cause, desire, boost) |
| throttle(noun, substance, agent, chemical) |
| trigger(noun, charge, cause, start, boost) |
| urge(noun, feeling, drive, start, passion) |
| yeast(noun, change, agent, chemistry) |
| effector(noun, desire, urge, spur, lure) |
| influence(noun, feeling, drive, passion, desire) |
| motive(noun, charge, feeling, drive, cause) |
| chemical(noun, agent, chemistry, chemical reactor) |
| catalysis(noun, desire, urge, spur, lure) |
| radical(noun, progress, spur, incentive, political agitator) |
| urger(noun, desire, urge, spur, lure) |
| accelerator pedal(noun, expression, idiom, substance, agent) |