The term “sus” is a slang word for “suspicious” or “suspect”, which can be used to say when something is questionable or shady.
In England the term is used as a name for a certain type of law, called “sus law”.
The term “sus” has first appeared in England as “sus law”, a name for the “stop-and-search” law which is allowed to the police force to arrest a suspected person if they appeared to be in violation of the Vagrancy Act of 1824.
The British shortening dates back to the 1950s but an earlier variation was already used in 1930s called “suss out”.
Since the new era anti-racist movements the formerly used “sus law” which was against the black and ethnic people in the 1970-1980s was scrapped because of a campaign called “Scrap Sus”.
It was officially outlawed in 1981,but later Black people started using it as a slang on the internet in the early 2000s.
The term “sus” is often used in posts on social media sites like Twitter, Instagram and Facebook, where people use it to react to something shady or questionable.
You can also find the term being used in law books or even court cases which discuss former laws in the US and UK.