The most common and most likely answer to this crossword clue is the 15 letter word CIRCUMNAVIGATED
I've seen this crossword clue in The Guardian
C
I
R
C
U
M
N
A
V
I
G
A
T
E
D
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 CIRCUMNAVIGATED mean?
CIRCUMNAVIGATED verb- To travel completely around somewhere or something, especially by sail.
- To circumvent or bypass.
- To sail around the world.