| A | B |
|---|
| insatiable | incapable of being satisfied (Prefix: in/im = not) |
| intrepid | having no fear, dauntless (Prefix: in/im = not) |
| inviolable | secure and thus cannot be violated (Prefix: in/im = not) |
| unfettered | free from restraints, liberated (Prefix: un = not) |
| unfounded | groundless, without substance, false (Prefix: un = not) |
| unorthodox | not following established ways of thinking Prefix: un = not) |
| unparalleled | unequaled (Prefix: un = not) |
| unremitting | unrelieved, relentless, ceaseless (Prefix: un = not) |
| unscathed | unhurt, unharmed (Prefix: un = not) |
| immutable | unchanging |
| impartial | unbiased, treating all equally |
| impious | lacking reverence, disrespectful |
| inauspicious | not favorable |
| incorporeal | without material form or substance |
| incorrigible | incapable of being reformed |
| indefatigable | incapable of being fatigued, having great stamina |
| unfazed | calm, not disturbed |
| unflappable | not easily upset, calm |
| unsubstantiated | not proven |
| unwarranted | lacking justification |
| in/im | not |
| un | not |
