The most common and most likely answer to this crossword clue is the 8 letter word FRABJOUS
I've seen this crossword clue in The Guardian
F
R
A
B
J
O
U
S
More clues leading to the result FRABJOUS
Buddy explains!

The straight part
We know that "wonderful for 22" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wonderful for 22 = frabjous.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 FRABJOUS mean?
FRABJOUS adjective- Fabulous, joyous; great, wonderful.