a slang for "Ash-main" in the video game Rainbow Six Siege. People who mainly play the character Ash is a "Shh-main". Due to Ash's rushing characteristic and glitchy hit-box mechanic, she's popularly disregarded and unfavored by the opposite team. Thus to avoid being scorned upon, Ash-mains typically silence the word Ash, hence the "Shh".
"What are you in Siege?"
"Don't tell anyone... I'm a Shh-main."