| impavid(strong, tough, bold, resolute, spirited) |
| impetuous(adjective, careless, wild, bold, thoughtless) |
| imprudent(adjective, careless, wild, bold, thoughtless) |
| impudent(adjective, mad, bold, naughty) |
| incautious(adjective, careless, wild, bold, thoughtless) |
| indiscreet(careless, wild, thoughtless, impulsive, negligent) |
| indomitable(strong, tough, vigorous, noble, bold) |
| injudicious(careless, thoughtless, impulsive, reckless, hasty) |
| insensible to fear |
| insuppressible(careless, thoughtless, impulsive, reckless, hasty) |
| irrational(careless, thoughtless, impulsive, reckless, hasty) |
| irresponsible(adjective, careless, wild, bold, thoughtless) |
| irreverent(adjective, mad, bold, naughty, impudent) |
| jaunty |
| jeopardous(adjective, safety, dangerous) |
| jumping to conclusions(expression, idiom, careless, thoughtless, impulsive) |
| lionhearted(strong, tough, noble, bold, resolute) |
| lippy(adjective, mad, bold, naughty, impudent) |
| madcap(adjective, careless, wild, bold, thoughtless) |
| malapert(adjective, mad, bold, naughty, impudent) |