The word melancholy means a state of utter dejection.
The word euphoria means healthy the word has travelled far in contemporary times and its meaning is eluded with other terms such as paradise, elation, exhilaration etc.
The words when coined  together forms an oxymoron and hence gives meaning to the meaningless.
Ever thought how melancholy could be euphoric and how euphoria could be melancholic? Hola! to some melancholy and euphoric times along with a flabbergast towards the end of the book.