1. Suspicious: This is the most common meaning of "suss." It means to be suspicious of something or someone, to think that something is not right or is being hidden.
Example: "I'm getting a suss vibe from that guy. I think he's lying."
2. Understand: In some dialects of English, "suss" can mean to understand or figure something out.
Example: "I can't suss out what she's trying to say."
3. Check out: This meaning is more specific to Australia and New Zealand. "Suss" can mean to check out something or someone, to investigate or explore.
Example: "Let's suss out the new cafe down the road."
The meaning of "suss" can be quite subtle and can vary depending on the speaker and the situation. However, it generally implies a sense of caution, skepticism, or investigation.