| 100% | INDELIBLE | 9 | Like pen marks that cannot be erased |
| 62% | INDELIBLE | 9 | Pen with ink that cannot be erased |
| 53% | INDELIBLE | 9 | Permanent ink that cannot be erased |
| 45% | PERMANENT | 9 | Like markers that are hard to erase |
| 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 |
| 38% | ELEMENT | 7 | Chemical substance that cannot be broken down |
| 38% | DEADLETTERS | 11 | Mail that cannot be delivered or returned |
| 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 |
| 37% | CARETS | 6 | Marks that look like inverted v's |
| 37% | SCAR | 4 | Mark that may be emotional or physical |
| 37% | NOTCH | 5 | Marking that's been scratched in wood |
| 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% | DOTS | 4 | Marks that are raised in the Braille alphabet |
| 36% | SMUDGE | 6 | Mark that might be left with greasy fingers |
| 36% | SCAR | 4 | Mark that may be covered by a tattoo |
| 35% | DATESTAMP | 9 | Mark that shows exactly when a letter was posted |
| 35% | DASH | 4 | Punctuation mark that looks like a hyphen |
| 35% | STAIN | 5 | Dirty mark that is not easily removed |
| 35% | TIME | 4 | Something that cannot be stopped but once lost, cannot be brought back |
| 35% | OVINE | 5 | Like ones that are fleeced |
| 35% | UNPAID | 6 | Like bills that are overdue |