nonexistent
Not existing at all; completely not real or present.
Nonexistent means something that doesn't exist at all, something that isn't real or present anywhere. If your teacher asks about homework you forgot to do, you might nervously explain that your completed assignment is currently nonexistent. When archaeologists search for a lost city but find nothing, they might conclude the city is nonexistent or perhaps just hasn't been discovered yet.
The word describes a total absence: absolutely nothing is there. Unicorns are nonexistent creatures, unlike pandas, which are real but endangered. Your chances of winning the lottery might feel nonexistent, but they do technically exist as a very tiny number. True nonexistence means zero, nothing, not there at all.
People sometimes exaggerate by calling things nonexistent when they really mean extremely rare or minimal. A student might complain their free time is nonexistent during exam week, though they probably do have a few minutes here and there. The word can carry a sense of frustration or disappointment: when something you need or want is nonexistent, you're completely out of luck.