The most common and most likely answer to this crossword clue is the 8 letter word LOCKSTEP
I've seen this crossword clue in The Guardian
L
O
C
K
S
T
E
P
More clues leading to the result LOCKSTEP
Buddy explains!

The straight part
We know that "Way to march" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case way to march = lockstep.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 LOCKSTEP mean?
LOCKSTEP noun- A step whereby the toe of one man is brought very close to the heel of the man in front.
- Close connection, unison, rigid synchronization.
- An inflexible, rigid or stifling pattern.