sup
interj. B2 Upper Intermediate US //ˈsəp// UK //sˈʌp// sup
interj. a very casual way to say hello or ask what is happening. It is a shorter version of the phrase 'What's up?'.
interj. a highly informal greeting or inquiry into current events. Functions as a clipped form of the interrogative 'What is up?'.
Sup, man? How was your weekend?
He didn't even look up from his phone, just gave a quick nod and said 'sup' as I walked into the room.
While 'sup' serves as a convenient shorthand in digital messaging, using it in a professional email might suggest a lack of respect for the recipient's status.
Usage
Used almost exclusively in spoken English or informal text-based communication; often functions as a phatic greeting requiring no literal answer.