The most common and most likely answer to this crossword clue is the 5 letter word POACH
I've seen this crossword clue in The Guardian
P
O
A
C
H
Buddy explains!

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 POACH mean?
POACH noun- The act of cooking in simmering liquid.
- To cook something in simmering liquid.
- To be cooked in simmering liquid
- To become soft or muddy.
- To make soft or muddy.
- To stab; to pierce; to spear, as fish.
- To force, drive, or plunge into anything.
- To begin and not complete.
- The act of taking something unfairly, as in tennis doubles where one player returns a shot that their partner was better placed to return.
- To take game or fish illegally.
- To take anything illegally or unfairly.
- To entice (an employee or customer) to switch from a competing company to one's own.