Solidness1. (n.) State or quality of being solid; firmness; compactness; solidity, as of material bodies.
2. (n.) Soundness; strength; truth; validity, as of arguments, reasons, principles, and the like.
Thesaurus Entries
THI, accord, accordance, addition, adjunct, affairs, affiliation, affinity, agreement, airlessness, airtight secrecy, alikeness, alliance, analogy, aping, approach, approximation, assemblage, assimilation, association, avarice, bond, cheapness, chumminess, close secrecy, closefistedness, combination, community, compactness, comparability, comparison, concealment, confinement, confines, conformity, congestedness, congestion, connectedness, connection, consistence, consistency, contiguity, contrariety, convergence, copying, correspondence, crowdedness, crypticness, dealings, deduction, denseness, density, discreetness, discretion, disjunction, environs, evasion, evasiveness, familiarity, filiation, firmness, foreground, gluiness, hair, hairbreadth, hairsbreadth, hardfistedness, hardness, hiddenness, hoarding, homology, hugger-mugger, hugger-muggery, humidity, humidness, identity, illiberality, imitation, immediacy, immediate foreground, impenetrability, impermeability, imporosity, incapaciousness, incommodiousness, incompressibility, indisposition to speak, inseparableness, intercourse, intimacy, intimate acquaintance, jammedness, junction, lack of meaning, lack of message, liaison, likeness, likening, limitation, link, linkage, linking, mateyness, meaninglessness, metaphor, mimicking, miserliness, mugginess, mutual attraction, narrow gauge, narrowness, nearness, neighborhood, nighness, oppression, oppressiveness, palliness, parallelism, parity, penny-pinching, precinct, propinquity, proximity, purlieus, rapport, relatedness, relation, relations, relationship, relative density, resemblance, restrictedness, restriction, sameness, secrecy, secretiveness, secretness, semblance, similarity, simile, similitude, simulation, slenderness, solidity, solidness, special affinity, specific gravity, spissitude, stickiness, stinginess, straitness, strictness, stuffiness, subterfuge, swelter, sympathy, temperature-humidity index, the dark, thickness, tie, tie-in, tight purse strings, tight squeeze, tightfistedness, tightness, uncommunicativeness, unconversableness, ungenerosity, union, unsociability, vicinage, vicinity, viscidity, viscosity, viscousness