n. a large, dense group of twitter users and/or bots who gather around a twitter target.

v. to move in large numbers to crowd, overrun, and target a twitter user's tweets and profile to chastise, abuse, and tweet at them for real or perceived wrong action(s), ideas, or attention.

v. the act of moving as a swarm or flocking to someone's twitter account to tweet mean things at them.
"The dude was wrong. So we Twitter swarmed him".

"Ed Sheeran was twitter swarmed by Game of Thrones fans who were unhappy with his cameo. He quit Twitter."
by MTL DeSweetie July 20, 2017
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