面識がある means you both know each other’s face/ have quickly met before, but never really talked.
顔見知り means literally that you have seen their face before. It means the same as 面識がある, but it’s less formal.
知り合い means acquaintance in a more generic way. You know each other, but you are not close.
知人 is like 知り合い, but more formal.

. But I think I would have at least looked at the people who were coming.


There are several things I was hoping to get out of this book club, but I didn’t think that an expanded knowledge of English literature would be one of them.