Heart, across, bulky, abundant, abounding in, dense, clotted, as thick as two short planks, croaking, broad, as thick as thieves, centre, and core are all synonyms for thick. Faint, vague, and unfriendly are these antonyms of thick. And here are another 199 synonyms for thick.
1. stocky
2. heavy
3. profuse
4. teeming
5. opaque
6. stiffened
7. brainless
8. hoarse
9. marked
10. intimate
11. centre