The most common and most likely answer to this crossword clue is the 3 letter word ITS
I've seen this crossword clue in Financial Times
I
T
S
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.
What does ITS mean?
ITS noun- One who is neither a he nor a she; a creature; a dehumanized being.
- The person who chases and tries to catch the other players in the playground game of tag.
- The game of tag.
- Sex appeal, especially that which goes beyond beauty.
- Sexual activity.
- A biological force that inhabits living beings, according to the vitalist approach of Georg Groddeck.
- The one (or ones) belonging to it.