| 不 | 아닐 불, no, not; un-; negative prefix (4) |
| 不可能- | 불가능하다 | impossible (conjugate verb) |
| 不可避- | 불가피하다 | inevitable, unavoidable (conjugate verb) |
| 不過 | 불과 | only, not more than |
| 不過- | 불과하다 | nothing more than (conjugate verb) |
| 不拘- | 불구하다 | deformity, malformation (conjugate verb) |
| 不利- | 불리하다 | to be disadvantageous, unfavorable (conjugate verb) |
| 不滿 | 불만 | dissatisfaction |
| 不法 | 불법 | illegal |
| 不殺生 | 불살생 | ahimsa |
| 不安 | 불안 | uneasiness, anxiety |
| 不安- | 불안하다 | to be uneasy, anxious (conjugate verb) |
| 不完全- | 불완전하다 | to be imperfect (conjugate verb) |
| 不利益 | 불이익 | disadvantage, drawback |
| 不恥下問 | 불치하문 | Don't be afraid to enquire of your juniors |
| 不便 | 불편 | inconvenience |
| 不便- | 불편하다 | to be unpleasant (conjugate verb) |
| 不平 | 불평 | dissatisfaction |
| 不平等- | 불평등하다 | inequality (conjugate verb) |
| 不必要- | 불필요하다 | to be unnecessary (conjugate verb) |
| 不幸 | 불행 | unhappiness |
| 不幸- | 불행하다 | to be unfortunate (conjugate verb) |
| 不確實- | 불확실하다 | be uncertain (conjugate verb) |