from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. Slang To infer or discover; figure out: "I think I'm good at sussing out what's going on” ( Ry Cooder).
- transitive v. Slang To size up; study: "Suss out the designers in whom you are interested” ( Lucia van der Post).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Suspicious.
- n. Suspicious behaviour; the act of loitering with intent.
- v. To arrest for suspicious behaviour.
- v. To discover, infer or figure out.
- v. To study or size up, to check out (examine).
- n. Social nous.
from The Century Dictionary and Cyclopedia
- A variant of soss.
Probably short for suspect.(American Heritage® Dictionary of the English Language, Fourth Edition)
From suspicious. (Wiktionary)
From suspect; originally suss out ("to investigate"). (Wiktionary)