| impetuous(adjective, strong, severe, intense, violent) |
| infuriated(adjective, strong, severe, intense, violent) |
| intemperate(adjective, enthusiastic, ill, sick, fervent) |
| intense(adjective, strong, severe, violent, terrible) |
| intolerant(adjective, enthusiastic, ill, sick, fervent) |
| inverse(adjective, opposite) |
| irrational(adjective, wild, silly, foolish, hot) |
| just plain nuts(expression, idiom) |
| keen(adjective, enthusiastic, ill, sick, fervent) |
| loopy |
| lunatic(silly, foolish, hot, crazy, mad) |
| mad-dog(adjective, enthusiastic, ill, sick, fervent) |
| malevolent(adjective, strong, severe, intense, violent) |
| malign(adjective, strong, severe, intense, violent) |
| maniacal(silly, foolish, hot, crazy, mad) |
| manic(adjective, crazy) |
| menacing(adjective, strong, severe, intense, violent) |
| mental(silly, foolish, mad, insane, unwise) |
| moonstruck(silly, foolish, mad, insane, unwise) |
| narrow-minded(adjective, enthusiastic, ill, sick, fervent) |