ˈsɑlɪd ˈsɒlɪd səˈlɪdɪti 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 the quality of being substantial or having substance the consistency of a solid 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