| hustle(noun, passion, spirit, cheat, speed) |
| immovability(noun, temper, determination, resolution, composure) |
| inclination(noun, passion, spirit, determination, enthusiasm) |
| indefatigability(noun, temper, determination, resolution, composure) |
| industry |
| inflexibility(noun, resolve, determination, firmness, persistence) |
| initiative(noun, passion, spirit, determination, enthusiasm) |
| intensity(noun, passion, spirit, determination, enthusiasm) |
| intentness(noun, passion, spirit, cheat, speed) |
| intestinal fortitude(noun, expression, strength, resolve, determination) |
| intransigence(noun, resolve, determination, firmness, persistence) |
| intrepidity(noun, strength, determination, courage, firmness) |
| keenness(noun, passion, spirit, determination, enthusiasm) |
| loyalty |
| mania(noun, passion, spirit, determination, enthusiasm) |
| mettle(noun, strength, determination, courage, firmness) |
| moxie(noun, strength, resolve, determination, resolution) |
| nerve(noun, strength, resolve, determination, courage) |
| obduracy(noun, resolve, determination, firmness, persistence) |
| pith(noun, strength, determination, courage, firmness) |