| ingenuity(noun, intelligence, intellect, talent, cleverness) |
| inquiring mind(noun, expression, acuity, officiousness) |
| inquiringness(noun, acuity, officiousness) |
| inspiration(noun, intelligence, intellect, talent, cleverness) |
| interestingness(noun, acuity, officiousness) |
| intrusiveness(noun, acuity, officiousness) |
| inventiveness(noun, intelligence, intellect, talent, cleverness) |
| keenness |
| knack(noun, intelligence, intellect, talent, cleverness) |
| know-how(noun, understanding, mind, intelligence, competence) |
| master(crackerjack, whiz, powerhouse) |
| mastermind(intellect, prodigy) |
| mature(noun, intelligence, intellect, talent, cleverness) |
| maturity(noun, intelligence, talent, cleverness) |
| meddlesomeness(noun, acuity, officiousness) |
| mental acquisitiveness(noun, expression, acuity, officiousness) |
| no slouch(expression, crackerjack, whiz, powerhouse) |
| officiousness(noun, acuity) |
| old pro(expression, crackerjack, whiz, powerhouse) |
| old war-horse(expression, crackerjack, whiz, powerhouse) |