Student or Learner
What is the meaning of the word mean in the following examples?
It is adjective for sure. It is simply the title of a movie!
In AmE, "mean girls" refers to the groups of girls (usually in high school) who band together and think that they're the prettiest, the coolest and the best. Once they've formed their clique they relish in mocking girls who are not part of their group. They'll make insulting remarks about them in the corridors at school ("Oh my God, I can't believe she wore those jeans. Doesn't she realize how big her butt looks??!") and post nasty Facebook or Twitter messages about them ("Everybody knows that Mary is a slut!). "Mean girls" are basically bullies.