The most common and most likely answer to this crossword clue is the 4 letter word BOON
I've seen this crossword clue in The Guardian
B
O
O
N
More clues leading to the result BOON
- Old Boy turns up, referring to something useful
- Favour element without Republican
- New online community member returns gift
- Favour element forgoing resistance
- Gift number passed back?
- Be vocal in opposition to new benefit
- Express disapproval of new gift
- Idiot abandons woodwind, which could be a blessing
- Favour beginner after swapping tips
- Audibly disapprove of new gift
Buddy explains!

The straight part
We know that "benefit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case benefit = boon.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 BOON mean?
BOON noun- A prayer; petition.
- That which is asked or granted as a benefit or favor; a gift or benefaction.
- A good thing; a blessing or benefit; a thing to be thankful for.
- An unpaid service due by a tenant to his lord.
- Good; prosperous.
- Kind; bountiful; benign.
- (Now only in boon companion) gay; merry; jovial; convivial.
- The woody portion of flax, separated from the fiber as refuse matter by retting, braking, and scutching.