| hassling(verb, irritating) |
| humoring |
| impetus(noun, charge, cause, boost, spur) |
| impulse(noun, charge, cause, boost, spur) |
| incentive(noun, charge, cause, boost, spur) |
| incitation(noun, charge, cause, boost, spur) |
| incitement(noun, charge, cause, boost, spur) |
| inducement(noun, charge, cause, boost, spur) |
| instigation(noun, charge, cause, boost, spur) |
| invitation(noun, charge, cause, boost, spur) |
| irking(verb, irritating) |
| kick(noun, charge, cause, boost, spur) |
| motivation(noun, charge, cause, boost, spur) |
| motive(noun, charge, cause, boost, spur) |
| nettling |
| propellant(noun, charge, cause, boost, spur) |
| provocation(noun, charge, cause, boost, spur) |
| push(noun, charge, cause, boost, spur) |
| shot in the arm(noun, expression, idiom, charge, cause) |
| spiting |