| cagey(adjective, smooth, keen, sharp, smart) |
| calculating(adjective, smooth, reasonable, keen, sharp) |
| cat-eyed |
| cerebral(adjective, reasonable, keen, deep, rational) |
| challenging(adjective, advance, view, success, perhaps) |
| clear-eyed |
| cogent |
| cogitative(adjective, reasonable, keen, deep, rational) |
| commonsensical(adjective, perceptive) |
| contemplative(adjective, reasonable, keen, deep, rational) |
| crafty(adjective, smooth, keen, sharp, smart) |
| cunning(adjective, smooth, keen, sharp, smart) |
| cutting(sharp, smart, intelligent, clever, astute) |
| deep(adjective, reasonable, keen, sharp, smart) |
| deliberative(adjective, reasonable, keen, deep, rational) |
| dim-sighted(adjective, myopic) |
| discriminating(sharp, smart, intelligent, wise, clever) |
| earnest(adjective, reasonable, keen, deep, rational) |
| engrossed(adjective, reasonable, keen, deep, rational) |
| eye-minded |