| 100% | SEINE | 5 | Boundary between Paris’s Twelfth and Thirteenth Arrondissements |
| 40% | COASTLINE | 9 | Boundary between land and water |
| 40% | ERIE | 4 | Lake ___ located on the International Boundary between Canada and the U.S. |
| 39% | RIOGRANDE | 9 | Boundary between the US and Mexico |
| 38% | LYON | 4 | City between Paris and Marseille |
| 38% | URALRIVER | 9 | Natural boundary between Europe and Asia |
| 38% | ALPS | 4 | Natural boundary between France and Italy |
| 38% | LYON | 4 | French city between Paris and Marseille |
| 37% | STYX | 4 | Boundary between the earth and the underworld, in myth |
| 36% | COASTLINE | 9 | Boundary strip between land and ocean |
| 36% | AMUR | 4 | River that forms the boundary between Manchuria and Russia |
| 35% | TERA | 4 | S.I. prefix between giga- and peta- |
| 35% | PQR | 3 | Letters between O and S |
| 35% | TERMINATOR | 10 | Boundary between the illuminated and darkened part of the moon, in astronomy |
| 35% | DRINA | 5 | River forming the boundary between Bosnia and Herzegovina and Montenegro |
| 35% | URAL | 4 | River forming part of the boundary between Europe and Asia |
| 35% | TWRCH | 5 | River that formed the ancient boundary between Brecknockshire and Carmarthenshire |
| 35% | DMZ | 3 | Area between N. and S. Korea |
| 34% | DRINA | 5 | River that forms the boundary between Bosnia and Herzegovina and Montenegro |
| 34% | RUBICON | 7 | Stream that formed the ancient boundary between Italy and Cisalpine Gaul |
| 33% | NEB | 3 | State between S. Dak. and Kan. |
| 33% | ANDREGIDE | 9 | Literature Nobelist between Hermann Hesse and T. S. Eliot |
| 32% | RHYMNEY | 7 | River in Wales forming the boundary between the historic counties of Glamorgan and Monmouthshire |
| 32% | ORANGE | 6 | River rising in the Drakensberg mountains that forms the boundary between South Africa and Namibia |
| 32% | ARAL | 4 | — Sea, lake east of the Caspian Sea that straddles the boundary between Uzbekistan and Kazakhstan |
| 31% | MASON | 5 | Charles —, astronomer who, with Jeremiah Dixon, surveyed the boundary between Maryland and Pennsylvania in colonial America |
| 31% | PARCS | 5 | Paris's Bois de Boulogne and others |
| 30% | URAL | 4 | ___ Mountains (boundary between Europe and Asia) |
| 30% | ARLO | 4 | Name that becomes another name if you put it between C and S |
| 29% | BORDERS | 7 | Boundaries between countries |