(adj)
Originating in various college campuses throughout the United States, it typically describes a state of prolonged absence from social life due to tests, term papers, etc.
Hey man, I haven't seen you around the house for like 3 days, where have you been?
Sorry, I've been ghost mode because of 3 finals and a 8 page essay, all in one week.
The act of disappearing from all social interactions whether it's texts, calls, or online- no one can reach you and without explanation, usually to recharge or avoid drama.