Sus

"Sus" is an abbreviation for "suspicious" or "suspect" on social media. It's often used when someone thinks that something is not quite right or doesn't seem trustworthy. 

For example, if someone sees a post or message that seems shady or sketchy, they might respond with "that's sus" or "I'm getting sus vibes from this." The term has become popularized by the game "Among Us", where players use the term to indicate that they suspect someone of being an impostor.