| Answer | Crossword Clue |
|---|---|
| WELL | A deep subject |
| profounder | (of a subject or thought) Demanding deep study or thought |
| profoundest | (of a subject or thought) Demanding deep study or thought |
| stabilate | a population preserved in a viable state though subject to extraordinary conditions eg microorganisms in deep freeze |
| ABYSS | Deep subject? |
| WELL | Deep subject? |
| CHASM | Deep subject? |
| OCEAN | Deep subject? |
| INNIE | Deep subject for bellybutton lovers? |
