1. filled or crowded with a large number of moving people or things

1. in a swarming manner; with a swarm or large crowd
Usage: often used predicatively after 'be'

Examples

• The beach was aswarm with tourists during summer vacation.
• The picnic area was aswarm with ants after we left food out.
• The harbor was aswarm with fishing boats at dawn.
• The garden became aswarm with butterflies in spring.
• The streets were aswarm with shoppers on Black Friday.
• The old building was aswarm with bees from a nearby hive.