substantial,
material,
real having substance or capable of being treated as fact; not imaginary; "the substantial world"; "a mere dream, neither substantial nor practical"; "most ponderous and substantial things"- Shakespeare
solidness -
the quality of being solid and reliable financially or factually or morally; "the solidity of the evidence worked in his favor"; "the solidness of her faith gave her enduring hope"
solidness -
the state in which a substance has no tendency to flow under moderate stress; resists forces (such as compression) that tend to deform it; and retains a definite size and shape
state of matter,
state (chemistry) the three traditional states of matter are solids (fixed shape and volume) and liquids (fixed volume and shaped by the container) and gases (filling the container); "the solid state of water is called ice"