| 100% | INDELIBLE | 9 | Pen with ink that cannot be erased |
| 67% | INDELIBLE | 9 | Permanent ink that cannot be erased |
| 61% | INDELIBLE | 9 | Like pen marks that cannot be erased |
| 49% | INDELIBLE | 9 | Ink that can't be erased |
| 49% | INDELIBLE | 9 | Ink that is impossible to erase |
| 42% | PCS | 3 | Notebooks that shouldn't be written on with pen |
| 42% | FOUNTAIN | 8 | ___ pen, water-based ink pen that is used broadly in calligraphy |
| 39% | TRESS | 5 | Lock that cannot be opened |
| 39% | SUNKCOST | 8 | Outlay that cannot be recovered |
| 39% | INCURABLE | 9 | Health condition that cannot be solved |
| 39% | ROOT | 4 | Tooth part that cannot be seen |
| 39% | ACE | 3 | Tennis serve that cannot be returned |
| 39% | HILITER | 7 | Pen with bright ink |
| 38% | ELEMENT | 7 | Chemical substance that cannot be broken down |
| 38% | DEADLETTERS | 11 | Mail that cannot be delivered or returned |
| 38% | STY | 3 | Pen with oink, not ink |
| 37% | MIRACLE | 7 | Event that cannot be explained by scientific laws |
| 37% | RUE | 3 | Feel regret over something that cannot be undone |
| 37% | SILENCE | 7 | Doctor Who aliens that cannot be remembered: the __ |
| 37% | ODDNUMBER | 9 | Uneven value that cannot be divided by 2 |
| 37% | READONLY | 8 | A protected file that cannot be changed or edited |
| 36% | YOUAWAKE | 8 | Question that cannot be answered if its answer is "no" |
| 36% | HYPOCRISY | 9 | “The only vice that cannot be forgiven,” per William Hazlitt |
| 36% | TESTATORS | 9 | Those with will power? |
| 35% | TIME | 4 | Something that cannot be stopped but once lost, cannot be brought back |
| 35% | GESTALT | 7 | Unified whole that cannot be described by the sum of its parts |
| 35% | TAT | 3 | Ink that might be on one's arm, for short |
| 35% | NIB | 3 | Pen part that may leak ink |
| 35% | BLOT | 4 | Ink stain that rhymes with "slot" |
| 35% | BIC | 3 | Pen that aptly rhymes with "click" |