Deep down, big, downwards, ardent, abstruse, delphic, absorbed, bass, bold, the briny, a great distance, and a long way are all synonyms for deep. Shallow and insincere are these antonyms of deep. And here are another 150 synonyms for deep.
1. extending far down
2. in depth
3. intense
4. clever
5. obscure
6. rapt
7. low-pitched
8. dark
9. the sea
10. far down