The most common and most likely answer to this crossword clue is the 11 letter word UNATTEMPTED
I've seen this crossword clue in The Times
U
N
A
T
T
E
M
P
T
E
D
Buddy explains!
The straight part
We know that "Not tried" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case not tried = unattempted.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 UNATTEMPTED mean?
UNATTEMPTED adjective- Not attempted.