(adjective) As one of the most beautiful words in the English dictionary, nebulous encompasses the full spectrum of obscurity in vocabulary. It is shapeless, formless, foggy, misty, vague, blurry hazy, etc; therefore it is difficult to see, comprehend or describe. The romanticism of this word lies in its opaque connotation. Although the English lexicon has numerous synonyms for ambiguity, nebulous depicts a mystery and a profound metaphysical confusion. It defines everything that is cryptic and shapeless. 
(via wordsnquotes)