The most common and most likely answer to this crossword clue is the 6 letter word CREAMY
C
R
E
A
M
Y
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The straight part
We know that "Rich and thick" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rich and thick = creamy.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CREAMY mean?
CREAMY noun- A horse with a cream-coloured coat.
- Containing cream.
- Of food or drink, having the rich taste or thick, smooth texture of cream, whether or not it actually contains cream.
- Of any liquid, having the thick texture of cream.
- Having the colour of cream.