The most common and most likely answer to this crossword clue is the 7 letter word UNEQUAL
I've seen this crossword clue in The Times
U
N
E
Q
U
A
L
More clues leading to the result UNEQUAL
- Different one in Paris Match
- Out of tune, qualitatively different
- Not even atypical American dropping out in favour of English queen
- Across the Channel, a peer's not the same
- Regularly suing peer is not being fair
- May’s successor dismisses judge as liberal and biased
- Not the same as having some immune quality
- Somewhat lacking, prune quality is just not the same
- Different passage of tune, quality
- A Parisian international out of game’s uniform? Not so
Buddy explains!

The straight part
We know that "different" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case different = unequal.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 UNEQUAL mean?
UNEQUAL noun- One who is not an equal.
- Not the same.
- Out of balance.
- Inadequate; insufficiently capable or qualified.