TRANQUIL'LITY, noun [Latin tranquillitas.] Quietness; a calm state; freedom from disturbance or agitation. We speak of the tranquillity of public affairs, of the state, of the world, the tranquillity of a retired life, the tranquillity of mind proceeding from conscious rectitude.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI