1. the unnecessary, indiscriminate killing of a large number of human beings or animals, as in barbarous warfare or persecution or for revenge or plunder.While the killings can be viewed as "unnecessary", "indiscriminate killing of a large number" implies what is meant by "large". "Large" can be a high number, the Germans lost over 750,000 soldiers in the Battle of Stalingrad over 2000 times the loss at Wounded Knee, and Stalingrad is NOT considered a "Massacre", thus "large" as used in this definition is NOT a high number. Thus "Large" must mean a high percentage (thus why I gave the Example of the Paxton Boys as a true Massacre, with the Paxton Boys you have almost 100% killed, the Native American losses were less then 50% thus fails this test as to the definition of "Massacre".
More on Stalingrad:
http://en.wikipedia.org/wiki/Battle_of_StalingradThis also applied to the second and fourth definition given, i.e. :
2.a general slaughter, as of persons or animals: the massacre of millions during the war.
4. to kill unnecessarily and indiscriminately, esp. a large number of persons.Both again are using large NOT as a high number but a high percentage.
The third and firth definition relates to sport's victories, hopefully you differentiate between Wounded Knee an a little league team that is defeated 20-0, thus I will ignore the third definition you cite.
Thus, once you establish that Large can not mean mere numbers, but something else, Wounded Knee fails on that count. Wounded Knee is NOT the Paxton boys with its almost 100% kill rate, nor the Nazis and their various Massacres where few if anyone survived.
Now, if you want to extend "Massacre" to include Wounded Knee what do you do with the Paxton Boys? Call what they did a "battle"? Terms are important. No one, especially I, have ever called Wounded Knee anything but a disaster, a Debacle, a butchery and even a "mistake" (A famous quote in regards to Napoleon's execution of the last heir to the Conte Branch of the Royal House of Bourbon "It was worse then a crime, it was a mistake" implying not only that what had been done was done badly BUT also should never have even been attempted, caused more harm then it did good even if the heir was guilty).
More on the last heir to the Conte Branch of the Bourbon Royal Family:
http://en.wikipedia.org/wiki/Louis_Antoine,_Duke_of_Enghien "Massacre" includes something more then mere bloodshed, it means an almost total desire to wipe out a ground. Now, some of the Soldiers at Wounded Knee had that desire, but as a whole the Soldiers did not (Nor their Officers). It is NOT a Paxton boys level of killings and I reserve the word "Massacre" to something on that level, a total desire by one group or person to wipe out another group or persons regardless of who is being killed and their ability to defend themselves.
There are a lot of "Massacres" during the Indian wars, starting in the 1600s and only ending in the late 1800s. At the same time there were battles, debacles, murders, and other crimes. I reserve the term Massacre to something not only uncalled for, but showing a clear desire by the Massacres to kill off everyone it the Massacre. We do NOT have that at Wounded Knee, it may sound like a fine point but if we want the English language to be understood we have to make sure the words we use are what we agree on.
In 1985 Philadelphia dropped a bomb on a House where some radicals lived, killed everyone in the house. It was a debacle and an mistake (and a salvage butchering of the people killed) but it does NOT appear the police WANTED the Mover personal killed (it was worse, the Police did NOT care if the Move people lived or died do to the bombing). Now, if evidence existed that the Philadelphia Police wanted the MOVE people dead AND that was their intentions (The Police did fire over 10,000 rounds into the house MOVE was in prior to the bombing) then the MOVE debacle would be a Massacre (Everyone died, so it passes the test of almost everyone being killed). The problem is showing the intent, the Police did NOT go into the house shooting everything that moved (as happens in most Massacres) but just dropped a bomb and cared less who was killed by the bomb.
While a good case of Massacre can be made for Dresden (The Western Allies wanted to kill as many Germans as possible by air power so to cool any German attempt at Guerrilla warfare) but Dresden is rarely called a Massacre (And it actually passes both tests, a huge loss of life in terms of Percentage AND it was quite clear the intention was to kill as many Civilians as possible).
Hiroshima and Nagasaki tends to fail the test for Massacre, while huge Civilian losses (and both cities had NEVER been bomb before, kept "safe" so the full affect of the A-bomb could be "judged" whenever their were hit) and almost everyone in the City Center was killed (Thus satisfied the high percentage part of a Massacre). The reason both cities had been picked was that both were places the Military made things, and in Japan that was in the homes people lived in. Japan did, and still does, a lot of work in private homes, where the wives then take the finished product to the Factory for more goods to make AND pay, the Factory is just the final assembly point (And this was the Norm BEFORE the B-29 started to Bomb Japan, became more so as Japan followed Germany's lead and disbursed manufacturing to its residential areas). Thus hitting the homes of the Japanese can be viewed as a Military target NOT just the Killing of Civilians. Thus the US has claim, and continues to claim the bombing of Hiroshima and Nagasaki was aimed at Military Targets NOT civilians. Again, no one is called the bombing of Hiroshima and Nagasaki as anything but horrific, but does it meet the definition of Massacre? Especially if the INTENT (As claimed by the US Government) is NOT to kill men, women and Children, but to hit the Japanese military manufacturing base?
Like Wounded Knee the people who claim Hiroshima and Nagasaki were "Massacres" have a tough hill to climb, NO ONE is saying what happened in all three places were NOT Horrific (and a Crime as while as a Mistake) but was the INTENT of the people during the killing to kill everyone just to kill them? What the Military says in all three cases may be rationalizations, but unless we have clear evidence of the Intent you can NOT claim any of the above (Except the Paxton Boys) meets the definition of Massacre.