1 throng, horde, army, host, multitude, hive, herd, mob, mass, drove, flood, stream, cloud, flock, pack, shoal, bunch:
Swarms of people showed up for our garden party.
2 throng, mass, crowd, congregate, flock, gather, flood, stream, flow:
The fans swarmed round the rock group.
3 swarm with.
Often, be swarming with. crawl with, abound in or with, throng with, teem with, burst with, bristle with, be overrun with:
In two minutes the place was swarming with police.