The most common and most likely answer to this crossword clue is the 10 letter word HALF-TRACK
I've seen this crossword clue in Financial Times
H
A
L
F
-
T
R
A
C
K
Buddy explains!
The straight part
We know that "Military vehicle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case military vehicle = half-track.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 HALF-TRACK mean?
HALF-TRACK noun- A vehicle combining both wheels and treads (caterpillar tracks).
- Describing such a vehicle; half-tracked