Definitions

1. adjective

not existing or having existence; nonexistent

“The idea of a perpetual motion machine is an unexisting concept in physics.”

2. verb

to cease to have existence or to be nonexistent

“The project will unexist by the end of the year due to lack of funding.”

3. noun

a thing that does not exist or have existence

“The unexisting creature of urban legend was said to roam the woods.”