A nebula is an interstellar CLOUD of dust, hydrogen, helium and other ionized gases. The term 'nebula' is derived from the Latin word for 'CLOUD'. The two crossword solutions for the term 'nebula' are 'MIST' (4 letters) and 'EAGLE' (5 letters). MIST is a collection of tiny water droplets suspended in the air, while an EAGLE is a large bird of prey with a hooked beak and powerful talons. Both MIST and EAGLE can be used to describe a nebula, as they both represent a collection of particles suspended in the air.