The most common and most likely answer to this crossword clue is the 2 plus 5 plus 1 plus 5 letter word TO CATCH A THIEF
T
O
C
A
T
C
H
A
T
H
I
E
F
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.