The most common and most likely answer to this crossword clue is the 11 letter word GEAR-CHANGE
I've seen this crossword clue in Financial Times
G
E
A
R
-
C
H
A
N
G
E
More clues leading to the result GEAR-CHANGE
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.