The Collaborative International Dictionary of English v.0.48:

Bloodshed \Blood"shed`\, n. [Blood + shed]
   The shedding or spilling of blood; slaughter; the act of
   shedding human blood, or taking life, as in war, riot, or
   murder.
   [1913 Webster]

WordNet (r) 3.0 (2006):

bloodshed
    n 1: the shedding of blood resulting in murder; "he avenged the
         bloodshed of his kinsmen" [syn: bloodshed, gore]
    2: indiscriminate slaughter; "a bloodbath took place when the
       leaders of the plot surrendered"; "ten days after the
       bloodletting Hitler gave the action its name"; "the valley is
       no stranger to bloodshed and murder"; "a huge prison battue
       was ordered" [syn: bloodbath, bloodletting, bloodshed,
       battue]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "bloodshed":
   all-out war, appeal to arms, armed combat, armed conflict, attack,
   bane, battle, belligerence, belligerency, blood, bloodbath,
   bloodletting, braining, butchery, carnage, combat, dealing death,
   destruction, destruction of life, dispatch, euthanasia, execution,
   extermination, fighting, flow of blood, genocide, gore,
   hostilities, hot war, immolation, kill, killing, la guerre,
   lapidation, martyrdom, martyrization, mercy killing, might of arms,
   military operations, murder, open hostilities, open war, poisoning,
   resort to arms, ritual killing, ritual murder, sacrifice, shooting,
   shooting war, slaughter, slaying, state of war, stoning,
   taking of life, the sword, total war, violence, war, warfare,
   warmaking, warring, wartime