Real Dictionary

swarm
A swarm of bees or other insects is a large group of them flying together.
A swarm of people is a large group of them moving about quickly.
If a place is swarming with people, it is full of people moving about in a busy way.
verb: When bees or other insects swarm, they move or fly in a large group.
verb: When people swarm somewhere, they move there quickly in a large group.

swarm in American English 1
a large number of bees, led by a queen, leaving one hive for another to start a new colony
intransitive verb: to fly off together in a swarm, as bees
noun: a body of honeybees that emigrate from a hive and fly off together, accompanied by a queen, to start a new colony
transitive verb: to swarm about, over, or in; throng; overrun

swarm in American English 2
to climb (a tree, mast, pole, etc.) using the hands and feet; shin (up)
to climb by clasping with the legs and hands or arms and drawing oneself up; shin

swarm in British English 1
noun: a group of social insects, esp bees led by a queen, that has left the parent hive in order to start a new colony
verb: (of small animals, esp bees) to move in or form a swarm

swarm in British English 2
verb: to climb (a ladder, etc) by gripping with the hands and feet