If someone is sussed, they are clever and know a lot about something such as clothes, pop music, or politics.

What does sussed mean in British slang?

/ (sʌst) / adjective. British informal well-informed; aware.

What is sussed short for?

1 : to find or discover (something) by thinking They had to suss out whether he was telling the truth. I'm trying to suss him out. What kind of person is he? I think I've got him sussed out. 2 : to inspect or investigate (something) in order to gain more knowledge He carefully sussed out the situation.