sociable; enjoying the company of others; liking to be with other people
I used to be quite gregarious when I was at university, and had many friends, but now I have become solitary and withdrawn.
grex gregis (flock, herd) (Latin)
agGREGation means gathering something together. Similarly GREGarious is a social person who likes groups or people for GRE we attend classes in groups Picture GREG, GARY, and RUSS all being GREGARIOUS