The most common and most likely answer to this crossword clue is the 9 letter word KILOMETRE
K
I
L
O
M
E
T
R
E
More clues leading to the result KILOMETRE
- Like metro, travelling some distance
- Like Metro to travel a distance
- Outfit infiltrated by devious mole supported by engineers in distance
- Distance travelled over in difficult mile trek?
- Tricky mile trek including middle of bog? A shorter distance
- Measure constant speed, essentially covering a length by metro transport
Buddy explains!

The straight part
We know that "distance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case distance = kilometre.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 KILOMETRE mean?
KILOMETRE noun- (official BIPM spelling, Australian, New Zealand, Irish, Indian and South African spelling) An SI unit of length equal to 103 metres. Symbol: km