| SPLEEN | Organ, once thought to be the seat of anger (6) |
| REMORA | The sucking-fish, once thought to be a hindrance to shipping (6) |
| LUNACY | Madness once thought to be brought about by changes of the moon (6) |
| ELIXIR | Chemical preparation once thought to be able to prolong life (6) |
| CHANCE | Pinball was once thought to be a game of luck or ___ |
| SPONGE | Sessile marine animal, once thought to be a plant (6) |
| EISNER | Disney figure once thought to be magical? |
| QUASAR | One of a number of astronomical bodies thought to be the most luminous objects in the universe (6) |
| EPONYM | What do we call a person whose name is thought to be the source of the name of a city, country, etc (6) |
| AFRICA | A vast land mass thought to be the site of the earliest humans (6) |
| BURIAL | The six plank-lined Anglo-Saxon graves found by the River Wensum are thought to be the earliest known such site in Britain (6) |
| DELPHI | Site thought to be the center of the world by ancient Greeks |
| ROCKYV | 1990 Stallone boxing film which at the time was thought to be the conclusion of its series |
| MAGNUM | Is a man using gum thought to be the full bottle? (6) |
| TROYES | French city thought to be the namesake for a system of weight |
| ARCHAEOPTERYX | The genus of feathered dinosaur that was once thought to be the oldest known fossil bird. Fossils are known from specimens found in the Solnhofen Limestone Formation in Bavaria, Germany, starting in 1 |
| BARNACLE | Crustacean once thought to be the origin of certain geese |
| ATOM | It was once thought to be the smallest particle of matter |
| HYADES | Cluster of five stars in Taurus, once thought to bring rain when they rise with the sun |
| CHEST | Coffer may be the seat of trouble to cougher (5) |
