WordNet (r) 3.0 (2006):

wartime
    n 1: a period of time during which there is armed conflict

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "wartime":
   all-out war, appeal to arms, armed combat, armed conflict, attack,
   battle, belligerence, belligerency, bloodshed, combat, fighting,
   hostilities, hot war, la guerre, might of arms,
   military operations, open hostilities, open war, resort to arms,
   shooting war, state of war, the sword, total war, war, warfare,
   warmaking, warring