The most common and most likely answer to this crossword clue is the 7 letter word REMANDS
I've seen this crossword clue in The Guardian
R
E
M
A
N
D
S
Buddy explains!

The straight part
We know that "Sends back" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sends back = remands.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 REMANDS mean?
REMANDS verb- To send a prisoner back to custody.
- To send a case back to a lower court for further consideration.
- To send back.