The term FS is an abbreviated form of For Sure. It is often used to indicate a high degree of concurrence or reinforcement in an informal conversation, in gameplay, and in social postings. Children and teens tend to use it to substitute longer answers such as definitely or absolutely. Being short, friendly, and harmless, it has already become one of the most popular abbreviations in such platforms as Tik Tok, Instagram, and Snapchat. Know more about what does fs mean