In these sentences, "mean" means "cruel," "vile," "hostile," "insulting," "rude," "unkind," "spiteful," etc. Looking over Google Translate's suggested Portuguese translations, the ones that looks right is probably "palavras cruelas." "Mean" in this sense means "words that are intended to hurt someone's feelings, words intended to make them feel bad." Older sister: "You're stupid, you're ugly, and nobody likes you." Younger sister: "Mom, my sister is saying mean things to me." It is, of course, a completely different word from "mean" in the sense of "to signify," "to denote."

Hi Raphael, 'Mean' in this case simply means 'not nice.' Best wishes, Alice

Mean is like rude.