The most common and most likely answer to this crossword clue is the 7 letter word WARTIME
I've seen this crossword clue in The Times
W
A
R
T
I
M
E
More clues leading to the result WARTIME
- Let out without being treated, back in troubled period
- Issue tender back in period of conflict
- Send out the inexperienced for call-up in 1914, perhaps?
- Tiny fellow enters Herts town — no peace now
- Throw out crude revolutionary period of conflict
- Write a novel about end of Nazism in period of conflict
- Period of fighting harsh, reflected by American magazine
- inexperienced revolutionary meeting the enemy when guns are fired
Buddy explains!

The straight part
We know that "Period of fighting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case period of fighting = wartime.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 WARTIME mean?
WARTIME noun- A period during which a war is in progress in a particular place.