Толковый словарь английского языка Oxford English Reference - nebulous

adj. 1 cloudlike. 2 a formless, clouded. b hazy, indistinct, vague (put forward a few nebulous ideas). 3 Astron. of or like a nebula or nebulae. Phrases and idioms nebulous star a small cluster of indistinct stars, or a star in a luminous haze. Derivatives nebulosity n. nebulously adv. nebulousness n. Etymology: ME f. F n{eacute}buleux or L nebulosus (as NEBULA)