| MILKVETCH | Purple ____ was once thought to improve dairy cow yields |
| CARROTS | Root vegetables synonymous with enticement and once thought to improve night vision, due to Britain's war-era propaganda, encouraging blackouts and covering up the RAF's use of newly invented radar sy |
| ATOM | It was once thought to be indivisible |
| CHANCE | Pinball was once thought to be a game of luck or ___ |
| SPLEEN | Malice was once thought to be the seat of melancholy (6) |
| EVILSPIRIT | Demon drink maybe that was once thought to cause illnesses? (4,6) |
| SPY | Explorer-botanist Andre Michaux was once thought to be one for the French |
| HAREBRAINEDIDEA | What human flight was once thought to be |
| NOBLEGAS | Peer regarded as hilarious here was once thought to be inert |
| 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 |
| WORMS | Eating a hair from a horse's forelock was once thought to be cure for what? (5) |
| MANDRAKE | Eurasian plant of the nightshade family whose forked root was once thought to have magic powers; Mandragora officinarum (8) |
| MICHAEL | Two rocky islands off the coast of County Kerry in southwestern Ireland are called the Skelligs. One, known as Skellig ___, was once home to a group of medieval monks, whose buildings, made of stone, |
| CHAMPIONSHIP | The EFL ____ was once called the Second Division |
| EVANS | Thom _, was once partnered by Iveta Lukosiute on Strictly Come Dancing (5) |
| OMEN | Birds circling overhead, it was once thought |
| BEARBAITING | Put up with teasing that was once thought entertaining (4-7) |
| PASTBELIEF | It was once thought incredible (4,6) |
| ITOO | "___ was once lost..." |
| ALDERNEY | Old dairy cow longing to be raised under tree |
