English
rationalness
From rational + -ness.
Formed from rational + -ness
Proto-Indo-European *h₂er- ‘to fit, to fix, to put together, to slot’
Latin reor ‘to compute’
Latin ratio ‘reason’
Latin rationalis ‘of or belonging to reason, rational, reasonable’
Old French rationel
English rational
Today it means
noun The quality or state of being rational.
Sources
Sources: Wiktionary, “rationalness”. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.
Etymograph / rationalness