Meaning a nightmare in which something good happens. Even though it is very uncommon to happen to people while you dream, it's something to definitely remember.
"Was Kyle your best nightmare last night??"
"Yeah! I don't even like him, and he was making out with me!"
"Yeah! I don't even like him, and he was making out with me!"
by tiger.16 October 19, 2016
Get the your best nightmaremug.