The most common and most likely answer to this crossword clue is the 10 letter word INDISTINCT
I've seen this crossword clue in Financial Times
I
N
D
I
S
T
I
N
C
T
More clues leading to the result INDISTINCT
- Obscure country’s losing a contest finally in court
- Feeling about girl that's vague
- Obscure charge involving U-turning idiots
- Dim policeman possessing an inborn intuitive power? Just the opposite
- Vague hunch about policeman
- Confused detective hampered by gut reaction
- Vague gut feeling about detective
- Obscure urge to embrace little girl
- Natural impulse about Diane isn’t clear
- I’d pulled back, protected by natural tendency? It’s not clear
Buddy explains!

The straight part
We know that "Dim" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case dim = indistinct.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 INDISTINCT mean?
INDISTINCT adjective- (of an image etc) not clearly defined or not having a sharp outline; faint or dim
- (of a thought, idea etc) hazy or vague
- (of speech) difficult to understand through being muffled or slurred