Just because a group of people have similar dreams does not mean anything. It could be just a dream.
It is very unlikely that your friends are having the same dream as you have. It is possible that your group shares common interests - let's say football - and so you all dream about football. But each individual's dream would be different and have a meaning specific to that person. Perhaps a better question to ask might be why your friends are telling you that they have the same dream as you have. It is possible that your friends are having a joke at your expense.
One can call a group of people with similar interests 'friends.' One becomes friends with another because they share a similar interest. One can have many friends that share the same interests as each other.
The devil in this dream might represent temptations or tendencies that you know you need to resist or avoid. The group of friends symbolize the different parts of yourself, some more easily tempted and others with greater resistance. The dream illustrates your efforts and determination to resist your temptations and to do what you know is right.
The dream indicates that you have information that could cause difficulty with certain groups of people.
There is no standard collective noun for a group of friends. The noun 'group' is a collective noun in the term 'a group of friends'.
cliques
No. This is just a way of "organizing" your friends list, similar to making a group in your email contacts.
what is group similar objects
Dream Street
Similar names for a group is called a gang
tissues are group of cell that perform a specific similar function.
amis mean friends. as 'amis' is masculine plural, it means either a group of male friends, or a group of mixed sex friends. a group of female friends would be 'amies'