nebulous

adjective

1. 1

   lacking definition or definite content

   nebulous reasons

   unfixed as were her general notions of what men ought to be"- Jane Austen

2. 2

   lacking definite form or limits

   gropes among cloudy issues toward a feeble conclusion"- H.T.Moore

   nebulous distinction between pride and conceit

3. 3

   of or relating to or resembling a nebula

   the nebular hypothesis of the origin of the solar system