Equability

Part of speech: noun

Definitions

1. The nature of possessing a steady and calm demeanor in various situations
2. The quality of maintaining a consistent and even disposition through changing circumstances
3. A characteristic of keeping emotional or mental balance without strong fluctuations

Etymology: "Equability" is a straightforward borrowing of Latin "aequabilitas", a noun built from "aequabilis", meaning "equal" or "uniform". The Latin adjective is itself formed from "aequus", "level, even, fair", with the suffix "-bilis", which signals capability or fitness, so the word literally describes the quality of being able to be made even or steady. Latin "aequabilitas" carried the sense of evenness and uniformity, whether of surfaces, motion, or proportion. English took the word from that Latin root, and its meaning narrowed over time from general uniformity toward a steadiness of mood. Within the English record, the idea of evenness is still visible: a person with equability keeps an even level of temper, neither rising nor sinking with circumstance, much as a flat, level surface keeps its line.

Synonyms: calmness, composure, serenity

Antonyms: agitation, turbulence, unrest