The "uninformed majority" in a Mafia game is a large faction (comprising over half of the starting player count) that does not know the identities of the other members of their faction. The standard name for this faction is the Town, even in themed games.
One could argue that the core focus of Mafia is the process of members of the Town identifying their allies and expelling their enemies.
There is usually only one Town in a game. It is not infeasible to have more, but it tends to strain the definition of Mafia.