"Wet dream"

In an e-mail group for Swedish translators, we have come to discuss the phrase "wet dream". Some of us feel that only men can have a wet dream, others that this is pure nonsense... Interesting, right?
This is the definition from Merriam-Webster Online:

"wet dream
Function: noun
Date: 1851

an erotic dream culminating in orgasm and in the male accompanied by seminal emission"

What do =you= say - must a wet dream be "accompanied by seminal emission"? Can both sexes have it? Does the phrase emanate from the involontary "wet dreams" that adolescent boys have?

Both sexes can have one and emissions are present in both cases. Webster's definition only covers the male case.