it basically means "
stop lying", "I
don't care" and "fuck off/fuck you" depending on the phrase it's used at.
first time used by
two students (Z.Yacine and Y.Abdelfettah - around
2020) when they were looking for a way to insult their professor without him being aware of it, later on it became their way of insulting everyone, then the word caught others' attention and a variety of other students started using it.
origin of the word is ترخف
person 1 : believe me bro, I tried did my best but did not
work
person 2 : chisme.
or
professor : you have to solve all these eauqtions by tomorrow, if not you
get an F.
student ; Sir, chisme.