Open English Wordnet
(s)obscure, vaguenot clearly expressed or understood“an obscure turn of phrase”, “an impulse to go off and fight certain obscure battles of his own spirit” (Anatole Broyard), “their descriptions of human behavior become vague, dull, and unclear” (P.A.Sorokin), “vague … forms of speech … have so long passed for mysteries of science” (John Locke)