- hardness
- n1. firmness, solidity, compactness, density; impenetrability, imperviousness, renitency, re-sistency; stiffness, rigidity, rigidness, inextensibility, inelasticity, inflexibility, unmalleability, intractability, unbendingness; immutability, unchangeableness, unal-terability; induration, ossification, petrification, fro-zenness, glaciation, insolubility.2. rigor, tightness, strictness, stringency, severity, stoicism; harshness, acerbity, callousness, induration, obdurateness, toughness, unimpressibility; want of feeling, unfeelingness, insensibility, insensitivity; im-passiveness, impassivity, indifference, coldness, iciness, sternness, grimness, sharpness; hard-heartedness, inhumanity, pitilessness, mercilessness; relentlessness, unyieldingness, inclemency, cruelty, truculence, ruth-lessness; gall, rancor, asperity, bitterness, acridness, virulence.3. difficulty, arduousness, toilsomeness, laboriousness, exhaustiveness, heaviness.
A Note on the Style of the synonym finder. 2014.