English
rationalize
Rationalize comes from French rationaliser ‘to rationalize’, and goes back to Latin reor ‘to compute’.
- Latinc. 75 BCE–200 CEreor1‘to compute’
- Latinc. 75 BCE–200 CEratiō2‘reason, reasoning, explanation, ground, motive, rationality, rationale, purpose’
- Latinc. 75 BCE–200 CEratiōnālis3‘rational, reasonable, of or possessing reason’
- Frenchc. 1600–presentrationnel4‘rational’
- Frenchc. 1600–presentrationaliser5‘to rationalize’
- Englishearliest quotation 1987rationalize5
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, Latin ratio
- 2 Wiktionary, Latin rationalis
- 3 Wiktionary, French rationnel
- 4 Wiktionary, French rationaliser
- 5 Wiktionary, English rationalize
- Earliest quotation in Wiktionary’s entry: 1987, Exhuming McCarthy: “Vested interest, united ties, / landed gentry, rationalize. /…”.
Earlier history not traced here. See Wiktionary.
Lineage
- Latinc. 75 BCE–200 CEreorWiktionary, Latin ratio‘to compute’
- Latinc. 75 BCE–200 CEratiōWiktionary, Latin rationalis‘reason, reasoning, explanation, ground, motive, rationality, rationale, purpose’
- Latinc. 75 BCE–200 CEratiōnālisWiktionary, French rationnel‘rational, reasonable, of or possessing reason’
- Frenchc. 1600–presentrationnelWiktionary, French rationaliser‘rational’
- Frenchc. 1600–presentrationaliserWiktionary, English rationalize‘to rationalize’
- Englishearliest quotation 1987rationalizeWiktionary, English rationalize. Earliest quotation in Wiktionary’s entry: 1987, Exhuming McCarthy: “Vested interest, united ties, / landed gentry, rationalize. /…”
Equivalent to rational + -ize
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
Linked words
through Latin reor ‘to compute’
rate, reasonable, irritate, ratify, 13 more
through Latin ratiō ‘reason, reasoning, explanation, ground,…’
Today it means
verb To make something rational or more rational.
Sources
Sources: Wiktionary, “rationalize”; the older steps come from the Wiktionary entries for Latin ratio, Latin rationalis, French rationnel, French rationaliser. 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 / Latin reor / rationalize