The most common and most likely answer to this crossword clue is the 6 letter word TIDIER
I've seen this crossword clue in The Daily Telegraph
T
I
D
I
E
R
More clues leading to the result TIDIER
- Better organised revolutionary holding one childish opponent back
- More presentable girl involved in row
- More organised inspector enters area of stand
- After a fashion I tried to become more presentable
- I had to break up row, becoming more orderly
- I tried somehow to be less messy
- More orderly, I had to get in line
- Getting properly organised, I tried to be less messy
- I had to stand in line — it’s neater
- I had to break up row, being smarter
Buddy explains!

The straight part
We know that "less messy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case less messy = tidier.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 TIDIER mean?
TIDIER noun- One who tidies.
- Arranged neatly and in order.
- Not messy; neat and controlled.
- Satisfactory; comfortable.
- Generous, considerable.
- In good time; at the right time; timely; seasonable; opportune; favourable; fit; suitable.
- Brave; smart; skillful; fine; good.
- Appropriate or suitable as regards occasion, circumstances, arrangement, or order.