The most common and most likely answer to this crossword clue is the 4 letter word UGLI
I've seen this crossword clue in Financial Times
U
G
L
I
More clues leading to the result UGLI
- Fruit cocktail guest eats up
- Fruit bought online needs unwrapping twice
- Picked up unappealing fruit
- Fruit revealed by lifting nail gun
- Uniform soldier eating large fruit
- Fruit very unlike peach, reportedly
- Some rail guard brought up fruit
- Fruit sounds unappealing
- Italian region getting peeled fruit
- Cross, discontented underdog on lithium
Buddy explains!

The straight part
We know that "fruit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fruit = ugli.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.