The most common and most likely answer to this crossword clue is the 3 letter word RAH
I've seen this crossword clue in The Times
R
A
H
Buddy explains!
The straight part
We know that "Some cheer, a hooray" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case some cheer, a hooray = rah.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 RAH mean?
RAH noun- A person (especially a student) with a posh accent who looks down on those who are "common".
- Posh.
- An exclamation of encouragement.
- An expression of surprise.
- An expression of admiration.
- An expression of frustration or anger.