The most common and most likely answer to this crossword clue is the 5 plus 4 letter word MINOR SUIT
I've seen this crossword clue in The Times
M
I
N
O
R
S
U
I
T
More clues leading to the result MINOR SUIT
- Small case for diamonds?
- Clubs, say, youngsters renounced without question
- Diamonds, for example, young girl put on smart dress
- Youngsters oddly shunning nudist clubs?
- Set close to smaller diamonds for example
- Unimportant match for clubs?
- Underage courtship in clubs?
- Child having uniform for clubs, maybe?
- Boy to match a kind of bridge hand
- Tourism flourishing around trendy clubs perhaps
Buddy explains!

The straight part
We know that "Clubs, say" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case clubs, say = minor suit.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.