What does “that’s sus” mean?
“Sus” is slang for “suspicious” or “suspect” and the phrase is used by young people to express skepticism, as in “that new kid who started a fight is sus.”
Instruction: What does “that’s sus” mean?
Context: 
Response: “Sus” is slang for “suspicious” or “suspect” and the phrase is used by young people to express skepticism, as in “that new kid who started a fight is sus.”