BIT OF A CLOUD is a term used to describe a small, thin cloud formation. The two crossword solutions for this term are WISP (4 letters) and NEBULA (6 letters). WISP is a term used to describe a small, thin cloud formation that is usually composed of ice crystals or water droplets. A NEBULA is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Both of these terms can be used to describe a BIT OF A CLOUD.