The term 'not solid' can be described by the crossword solutions of MIRY (4 letters), FLUID (5 letters), IFFY (4 letters), pied (4 letters), unset (5 letters), WISPY (5 letters), SPONGY (6 letters), and STRIPED (7 letters). MIRY is a term used to describe something that is muddy or boggy. FLUID is a term used to describe something that is able to flow freely. IFFY is a term used to describe something that is uncertain or unreliable. Pied is a term used to describe something that is multicolored or variegated. Unset is a term used to describe something that is not firmly fixed in place. WISPY is a term used to describe something that is thin, light, and insubstantial. SPONGY is a term used to describe something that is soft and easily compressed. STRIPED is a term used to describe something that has stripes or bands of color. All of these terms can be used to describe something that is not solid.