“2X” in rap slang can mean two things. It can be used like “4L” where it is used as a shortened version of the phrase “too excessive,” “too excess,” or “too much.” You might hear someone say it like:
“The violence in GTA is just 2x, bro.”
Another meaning for this slang is simply to double something or say it again twice. It is often used as a shortcut in a conversation. You might find it being used like this:
“For the voice recognition to work, you need to say the phrase 2x.”