Cryptic crossword clue
Bobby Charlton’s header, running fast after cut back by reserve 6,9

The most common and most likely answer to this crossword clue is the 16 letter word POLICE CONSTABLE

I've seen this crossword clue in The Guardian
P
O
L
I
C
E
Â
 
C
O
N
S
T
A
B
L
E

Buddy explains!

The straight part
We know that "Bobby" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bobby = police constable.
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.

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