| VISIONS | Nostradamus was thought to have them |
| SEER | Nostradamus was one |
| FELT | Baize-like fabric whose former "carroting" method of construction was thought to have given rise to the phrase "mad as a hatter" (4) |
| SALEMRIVER | NICK WAS THOUGHT TO HAVE DROWNED IN IT (DAYS, two words) |
| INNERTEMPLE | Which of the Inns of Court was thought to have begun in the 13th century when it housed the lawyers who advised the Knights Templar? (5,6) |
| OAK | According to tradition, what tree was associated with the god of thunder because it was thought to be the tree most likely to be hit by lightning? (3) |
| DEVIGENRE | For many years this type of simple polyalphabtic cipher was thought to be impregnable and was known as le chiffre indechiffrable, literally "the unbreakable cipher." |
| TALENT | Aptitude, flair - as Jeremy was thought to possess (6) |
| NEPTUNE | He was thought to be the main controller (7) |
| ROCKYV | 1990 Stallone boxing film which at the time was thought to be the conclusion of its series |
| KIDD | Pirate captain whose treasure was thought to be buried on Oak Island |
| PETREL | Storm ___ , seabird so named because it was thought to be a harbinger of rough weather (6) |
| CELANDINE | Yellow wild flower once called pilewort as it was thought to be good for haemorrhoids (9) |
| EMERALD | In ancient times, what gemstone was thought to cure diseases of the eye? (7) |
| OPAL | Lustrous gem that was thought to bring good luck in the Middle Ages |
| PEA | Miniature cork ball in a whistle; old name for a bird in the genus Pavo known collectively as a muster; or, a podded vegetable whose original name was thought to be plural (3) |
| ASPHODEL | A plant of the lily family that was thought to carpet Hades in Greek mythology (8) |
| EBONY | Dark wood once used for drinking cups, as it was thought to neutralize poison |
| CAMELOPARD | Archaic name for a giraffe, taken from two animals it was thought to resemble (10) |
| YGGDRASIL | In Norse mythology, the ash tree that was thought to overshadow the world, binding together earth, heaven and hell with its roots and branches |
