Out on Limbs

So I've come to realize there is no real opposite word for "nightmare".

The term "dream" is the umbrella for all mental fantasies, and "daydream" and "nightmare" have flawed definitions. Daydreams are when you are awake and fantasize, nightmares are when you're asleep and have a bad dream. There's no term for when you're asleep but have a good dream, nor is there a term for when you're awake and fantasizing about something bad.

If you think about it, it shouldn't be a matter of daydream, nightdream, daymare, and nightmare. That would be repetitive and make little sense. However, there should be something that splits things in twain for day/night as well as another for bad/good. If you chose to use "dream" as good, "mare" as bad, "day" as awake and "night" as asleep, then both day and night dreams would be good and both day and night mares would be bad. Except, that won't happen, so we'll have to continue saying "good dream", "nightmare", and then long-winded stories about how your daydreaming fantasies were good or bad. Very inefficient.