The most common and most likely answer to this crossword clue is the 10 letter word RETROGRADE
I've seen this crossword clue in The Daily Telegraph
R
E
T
R
O
G
R
A
D
E
More clues leading to the result RETROGRADE
- Backing note about Leningrad formerly removing leader
- Regret road is winding, going downhill
- Relating to attempt to reverse rule to stop commerce declining
- Backward reader got confused about the end of chapter
- Going back, regret road is up
- Going backwards, regret road being repaired
- Order great changes, going in a bad direction
- Reverse: regret road crumbling
- Backward trader, ogre needing replacement
- Deteriorating road — regret repairs
Buddy explains!

The straight part
We know that "Backward" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case backward = retrograde.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 RETROGRADE mean?
RETROGRADE adjective- Directed backwards, retreating; reverting, especially to an inferior state, declining; inverse, reverse; movement opposite to normal or intended motion, often circular motion.
- Counterproductive to a desired outcome.
- (of a body orbiting another) In the opposite direction to the orbited body's spin.
- Describing a metamorphic change resulting from a decreasing pressure or temperature.
- (by extension, of a person) A person who opposes social reforms, favoring the maintenance of the status quo, conservative.
- A degenerate person.
- The reversal of a melody so that what is played first in the original melody is played last and what is played last in the original melody is played first.
- To move backwards; to recede; to retire; to decline; to revert.
- To show retrogradation.