RE'ASONABLENESS, noun 1. The faculty of reason. [In this sense, little used.] 2. Agreeableness to reason; that state or quality of a thing which reason supports or justifies; as the reasonableness of our wishes, demands or expectations. the reasonableness and excellency of charity. 3. Conformity to rational principles. The whole frame and contexture of a watch carries in it a reasonableness - the passive impression of the reason or intellectual idea that was in the artist. [Unusual.] 4. Moderation; as the reasonableness of a demand.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI