The most common and most likely answer to this crossword clue is the 5 letter word EATER
I've seen this crossword clue in The Daily Telegraph
E
A
T
E
R
More clues leading to the result EATER
- Greengrocer, eg, sells this item which shoots, hard to shift
- Someone swallowing fire in Bow?
- Gnarled tree containing a type of fruit
- Sort of a tree, one seen in refectory?
- Something got by shaking a tree?
- Consumer worry that’s flipping concerning
- Consumer society rejected by holy festival
- One rousing game sees opener dismissed for 8 part 1? If so, it could be Jonathan
- Some people ate rare piece of fruit?
- Apple in a tree shaken about
Buddy explains!

The straight part
We know that "apple" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case apple = eater.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 EATER mean?
EATER noun- One who eats.
- An eating apple.
- One who performs fellatio or cunnilingus.
- A configuration of cells that appears to consume another configuration by gradually causing it to disappear.