The most common and most likely answer to this crossword clue is the 9 letter word MANHANDLE
I've seen this crossword clue in The Daily Telegraph
M
A
N
H
A
N
D
L
E
More clues leading to the result MANHANDLE
- Maltreat new worker interrupting bloke
- Haul or maul Paul or Saul, say?
- Crew name tug crudely?
- Mistreat crew worker left without paper
- Knock about a possible nickname for John Thomas!
- Push graduate to meet new so-called composer
- Be rough with Guy, say?
- Knock around chap with title
- Knock around with workers near the centre of Hartlepool
- Fellow worker the French treat roughly
Buddy explains!

The straight part
We know that "treat roughly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case treat roughly = manhandle.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 MANHANDLE mean?
MANHANDLE verb- To move something heavy by force of men, without aid of levers, pulleys, machine, or tackles.
- To assault or beat up a person.
- To mishandle; to handle roughly; to mangle.
- To control (a machine, vehicle, situation, etc.) by means of physical strength.