A transformation used to receive a 50x multipler of your base form. Goku was the first person in the anime to achieve this form. It is abberviated to SSJ. There are other forms of SSJ such as Ascended SSJ, Ultra SSJ, Controlled Super Sayian, SSJ2, SSJ3, Super Sayian God and Super Sayian Blue. The only Sayians to ever achieve this form in the main series are Bardock, Goku, Vegeta, Trunks, Goten, and Gohan.
Guy 1: Dude, did you see what happened in Dragon Ball Z yesterday ?
Guy 2: Yea, Goku turning Super Sayian 2 against Vegeta was epic.
Person 1: Want to come to my party next weekend? It's going to be lit.
Person 2: Sorry but I have to work on my paper.
Person 1: Bruh, that is so super anti lit.