The most common and most likely answer to this crossword clue is the 7 plus 9 letter word EXCLUDE (EXALTED)
I've seen this crossword clue in The Guardian
E
X
C
L
U
D
E
(
E
X
A
L
T
E
D
)
Buddy explains!
The straight part
We know that "send to Coventry" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case send to coventry = exclude (exalted).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.