The most common and most likely answer to this crossword clue is the 6 letter word ROPIER
R
O
P
I
E
R
Buddy explains!
The straight part
We know that "More tatty" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case more tatty = ropier.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 ROPIER mean?
ROPIER adjective- Resembling rope in appearance or texture, used especially of muscles that are thick or hard to the touch.
- Capable of forming rope-like or thread-like structures.
- Of poor quality; in poor health.
- (of milk or another liquid) Slimy, as after the action of Enterobacter aerogenes in syrup.