What Does /S Mean? (Using /S Online)/S means "Sarcasm".
Definition for /S/S means "Sarcasm". This is the most common definition for /S on Snapchat, WhatsApp, Facebook, and Twitter. Here is some more information about /S:
5: Extremely difficult to guess
Adults and Teenagers
Using /S on a Cell Phone (SMS Texts, Whatsapp, and Yubl)