The most common and most likely answer to this crossword clue is the 2 plus 5 letter word IN BUILT
I
N
B
U
I
L
T
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.
Crossword Answer definitions
IN BUILT adjective- Existing as an essential constituent; built-in; inherent; integral.