ancient or natural
| HISTORY |
| Word | Clue |
|---|---|
| FUEL | gasoline or natural gas |
| MOON | only natural satellite of Earth |
| ELDER | ancient |
| PLATO | ancient philosopher |
| RIVER | natural watercourse |
| DIMPLE | small natural indentation in the flesh |
| NUMBER | prime or natural |
| TALENT | marked natural ability or skill |
| FOUNTAIN | natural source of water |
| RESOURCE | natural or monetary |
| SOCRATES | ancient philosopher |
| ARISTOTLE | ancient philosopher |
| ATTRITION | natural wastage |
| CONFUCIUS | ancient philosopher |
| ARCHIMEDES | ancient mathematician |
| DEMOCRITUS | ancient philosopher |
| HERACLITUS | ancient philosopher |
| PYTHAGORAS | ancient mathematician |
| WILDERNESS | undisturbed natural environment |
| ERATOSTHENES | ancient mathematician |
| HISTORY | ancient or medical |
| DIOGENES | ancient philosopher |