The most common and most likely answer to this crossword clue is the 10 letter word OVERTAKING
I've seen this crossword clue in The Guardian
O
V
E
R
T
A
K
I
N
G
More clues leading to the result OVERTAKING
- Glaring as family Golf is going past
- Getting the better of blatant forgery, handing out fine
- Going beyond blatant: Herod maybe?
- Open a card in passing
- Passing old, green, family silver around
- Coming to pass in public with a ruler
- Clear article to appear before ruler’s passing
- Passing a man in game when it’s clear in front
- Passing undisguised, a monarch
Buddy explains!

The straight part
We know that "Passing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case passing = overtaking.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 OVERTAKING mean?
OVERTAKING verb- To pass a more slowly moving object or entity.
- To become greater than something else
- To occur unexpectedly; take by surprise; surprise and overcome; carry away
- The act by which one thing overtakes another.