The most common and most likely answer to this crossword clue is the 6 letter word RETAIN
I've seen this crossword clue in Independent
R
E
T
A
I
N
More clues leading to the result RETAIN
Buddy explains!

The straight part
We know that "Employ" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case employ = retain.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 RETAIN mean?
RETAIN verb- To keep in possession or use.
- To keep in one's pay or service.
- To employ by paying a retainer.
- To hold secure.
- To hold back (a pupil) instead of allowing them to advance to the next class or year.
- To restrain; to prevent.
- To belong; to pertain.