The most common and most likely answer to this crossword clue is the 4 letter word GOLD
I've seen this crossword clue in The Guardian
G
O
L
D
More clues leading to the result GOLD
Buddy explains!

The straight part
We know that "Wealth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wealth = gold.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 GOLD mean?
GOLD noun- A heavy yellow elemental metal of great value, with atomic number 79 and symbol Au.
- A coin or coinage made of this material, or supposedly so.
- A deep yellow colour, resembling the metal gold.
- The bullseye of an archery target.
- A gold medal.
- Anything or anyone that is very valuable.
- (in the plural) A grill (jewellery worn on front teeth) made of gold.
- To pyrolyze or burn food until the color begins to change to a light brown, but not as dark as browning
- Made of gold.
- Having the colour of gold.
- (of commercial services) Premium, superior.
- (of software) In a finished state, ready for manufacturing.
- Of or referring to a gold version of something