Question

Where do you suppose the term "massacre'' came from that describes this event

Answer 1

Assuming you're referring to the "Boston Massacre," the word "massacre" was used because it sounded much worse than what it actually once--since it was easer to rally support around a cause that sounded like a "massacre" instead of just a few people being killed. 

Answer 2

Answer;
It was a political propaganda term used by Paul Revere in the etchings he created after the incident.

Step-by-step explanation;
When Paul Revere first began selling his color prints of "The Bloody Massacre perpetrated in King Street" in Boston, he was doing what any like-minded patriot with his talents in 1770 would have done. He did it faster and more expeditiously than anyone else, including two other artist-engravers who also issued prints of the Massacre that year.