Figmental is an adjective that means imaginary. 

The Latin word fignare (feeg NARE ay) means ’to form’ or ‘contrive.’ By the late Middle English period, the word ‘figment’ came to mean something formed through our imagination. Our word of the day is the adjective form of the word. Here’s an example of it in use:

As a kid, I had a number of figmental conversations with people who weren’t actually there. I understood they were imaginary, but I was just having too much fun to let reality get in my way.