The most common and most likely answer to this crossword clue is the 9 letter word KNOTTIEST
I've seen this crossword clue in The Guardian
K
N
O
T
T
I
E
S
T
More clues leading to the result KNOTTIEST
Buddy explains!
The straight part
We know that "most tangled" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case most tangled = knottiest.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 KNOTTIEST mean?
KNOTTIEST adjective- Full of knots.
- Complicated or tricky; complex; difficult.