The most common and most likely answer to this crossword clue is the 8 letter word REVEILLE
I've seen this crossword clue in The Times
R
E
V
E
I
L
L
E
More clues leading to the result REVEILLE
- About to ring apple-picker with incorrect wake-up call
- Terribly vile leer — wake-up call
- Wake-up call concerning girl unwell inside
- Military call always recalled unwell European
- Right to quit dream about large loch — here's wake-up call
- Soldiers with blanket, asleep, essentially woken by this?
- Signal to wake First Lady, not so well after cycling
- Referring to mask, the French sounding alarm?
- In France she welcomes one after vicar’s early morning call
- Performed live, reel produces musical awakening
Buddy explains!

The straight part
We know that "Military call" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case military call = reveille.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 REVEILLE mean?
REVEILLE noun- The sounding of a bugle or drum early in the morning to awaken soldiers.