| 100% | STATE | 5 | Washington is the only one named for a president |
| 59% | MONROE | 6 | Only U.S. President besides Washington for whom a world capital is named |
| 56% | ERA | 3 | One may be named for a president |
| 54% | STATE | 5 | Only one bears the name of a U.S. president |
| 53% | EARTH | 5 | What is the only planet in our solar system not named for a deity? |
| 48% | PHD | 3 | Wilson was the only president with one |
| 47% | EMME | 4 | One-named model who was a spokesperson for Revlon in the late 1990s |
| 47% | TENDON | 6 | The most well-known one is named for a Greek hero |
| 47% | AMI | 3 | "___ the only one who thinks this is a bad idea?" |
| 46% | PATENT | 6 | Lincoln is the only U.S. president to have one |
| 46% | MBA | 3 | G.W. Bush is the only president who earned one |
| 46% | WALL | 4 | John ___, one of the highest-paid NBA players of 2019 who is a point guard for the Washington Wizards |
| 46% | PHD | 3 | Woodrow Wilson is the only U.S. president to have one |
| 46% | MBA | 3 | Bush Jr. is the only U.S. president to hold one |
| 46% | PHD | 3 | Woodrow Wilson was the only U.S. president to have one |
| 46% | AGE | 3 | 35 is the minimum for a U.S. president |
| 45% | MBA | 3 | CFO's degree, maybe (Bush is the only president to have one) |
| 45% | GRAPHICNOVEL | 12 | "Maus" is the only one to win a Pulitzer Prize (1992) |
| 45% | MAINE | 5 | The only U.S. state with a one-syllable name |
| 45% | NONET | 5 | Name for one of the 3x3 regions in a Sudoku grid |
| 45% | ERA | 3 | Historical period that may be named for a president |
| 45% | ERA | 3 | Time period that may be named for a president |
| 45% | AGE | 3 | 122 is the highest known one for a human |
| 44% | LABORUNION | 10 | Ronald Reagan is the only U.S. president who was also president of a … |
| 44% | MBA | 3 | Pres. George W. Bush was the only president to hold one of these degs. |
| 44% | ERA | 3 | Period that may be named for a president |
| 44% | CIVICLEADER | 11 | One for whom a street may be named |
| 44% | HEIRS | 5 | Ones gathering for the reading of a will |
| 44% | BLENDE | 6 | Name for zinc sulfide that is one letter short of a kitchen appliance |
| 44% | SKELETON | 8 | The Blue ridge coral is the only one that forms a __ |