Nickname for someone who is continually off work "sick", usually faking it because they are simply too lazy or irresponsible and can't be bothered to come in to work like the rest of us. Most of the time they don't even bother to call in with a reason.
Ultra Instinct Sicko Mode is the highest level of sicko mode that can currently be achieved. It is where a person ascends to the highest level of existence. This results in the sudden absolute peak of physical and intellectual prowess where a person can act purely on instinct. As such, this mode is another way of saying that they are immortal.
Sicko mode is a level of both intelligence and physical being in such one can achieve anything. This could be as simple as walking or as complex as explaining tier memes
Person 1: Hey man, you down to have a kickback at your place tonight?
Person 2: Not tonight no, I just came off some crazy fever, and am feeling a bit sickover.