The most common and most likely answer to this crossword clue is the 8 letter word TREASURE
I've seen this crossword clue in The Times
T
R
E
A
S
U
R
E
More clues leading to the result TREASURE
- Prize article mostly secure in box, perhaps
- Endless delight, of course, producing riches
- Nurse briefly with certain valuables
- Regularly target a certain masterpiece?
- Time to restore confidence having lost one small gem
- Special gift almost certainly something valuable
- Prize certain to be given after short walk
- Regularly target a certain valuable object
- Briefly handle certain wealth stored up
- Adore fund manager? Not quite
Buddy explains!

The straight part
We know that "wealth stored up" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wealth stored up = treasure.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 TREASURE mean?
TREASURE noun- A collection of valuable things; accumulated wealth; a stock of money, jewels, etc.
- Anything greatly valued.
- A term of endearment.
- (of a person or thing) To consider to be precious; to value highly.
- To store or stow in a safe place.
- To enrich.