Invariability(n.) The quality of being invariable; invariableness; constancy; uniformity.
Thesaurus Entries
assurance, balance, balanced personality, composure, confidence, constancy, constraint, control, cool, coolness, discipline, ease, easiness, equability, equanimity, equilibrium, erectness, fastness, firmness, homeostasis, imperturbability, independence, invariability, level head, levelheadedness, nerve, nonchalance, orthogonality, perpendicularity, plumbness, plungingness, poise, possession, precipitousness, presence of mind, reliability, restraint, right-angledness, right-angularity, rootedness, sang-froid, sangfroid, savoir faire, secureness, security, self-assurance, self-command, self-confidence, self-conquest, self-control, self-denial, self-discipline, self-government, self-mastery, self-possession, self-restraint, sheerness, solidity, soundness, squareness, stability, stable equilibrium, stable state, steadfastness, steadiness, steady nerves, steady state, steepness, substantiality, undeflectability, uniformity, unshakable nerves, unshakableness, up-and-downness, uprightness, verticalism, verticality, verticalness, well-regulated mind