Definitions

1. noun

a community or group of people closely united or associated

“The neighborhood was a tight-knit community that looked out for one another.”

2. adjective

closely united or associated

“The tight-knit family always had a strong bond with one another.”

3. verb

to cause or become closely united or associated

“The new policy has helped to tighten the community, making it a more tight-knit group.”