1. Tending to associate with others of one's kind and being fond of company: The authors of gritty novels often write about the gregariousness of bar flies, or men who converge in bars to drink.
2. Being marked by or indicating a liking for companionship; being sociable in an assemblage: The figurines on the shelf clustered together, their gregariousness looking as if they were animated after dark, getting together to talk about the children sleeping in the next room.
3. Living in contiguous nests but not forming a true colony; especially, with reference to wasps and bees: During his apprenticeship working on the agricultural research farm, Justin noticed the gregariousness of the wasps in the vicinity of the barns.