1. (a.) Cloudy; hazy; misty; vague; as, a nebulous description\.

2. (a.) Of, pertaining to, or having the appearance of, a nebula; nebular; cloudlike.

Cynthian abstract amorphous anagalactic asteroidal astral astrologic astrologistic astrologous astronomic astrophysical bland blind blurred broad castellatus celestial circumplanetary cirrose cirrous cislunar clear as mud cloud-flecked clouded cloudy collective cumuliform cumulous dark dim dirty empyreal empyrean equinoctial extragalactic faint featureless foggy fuzzy galactic general generalized generic gloomy hazy heavenly heavy heliacal ill-defined indefinite indeterminate indistinct intercosmic interplanetary intersidereal interstellar lenticularis lunar lunary lunate lunular lunulate mammatus meteoric meteoritic misty muddy murky nebular nebulose neutral nimbose nonspecific nubilous obscure opaque overcast overclouded pale planetal planetarian planetary planetesimal semilunar shadowy shapeless sidereal solar sphery squally star-spangled star-studded starry stellar stellary stormy stratiform stratous terrestrial thunderheaded transcendent turbid uncharacterized unclear undifferentiated unplain unspecified uranic vague wide zodiacal