The most common and most likely answer to this crossword clue is the 7 plus 6 letter word TENZING NORGAY
I've seen this crossword clue in Independent
T
E
N
Z
I
N
G
N
O
R
G
A
Y
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.