From Longman Dictionary of Contemporary Englishtight-knitˌtight-ˈknit adjective [usually before noun] RELATIONSHIPa tight-knit group of people are closely connected with each other a tight-knit island community
Examples from the Corpus
tight-knit• The Cajuns are a very tight-knit and family-orientated community.• Filipinos have established a tight-knit community in the city.• The tight-knit mining communities had their own traditions and tales, and in Ayrshire one miner's name was a legend.• The management and the team grew together into, in the early stages, a tight-knit organisation.• But, although the core of this group was quite small and tight-knit, the influence of their ideas was widely felt. 