rationalism

/ˈɹæʃ(ə)nəlɪzəm/

//ˈɹæʃ(ə)nəlɪzəm// noun

By · According to Wiktionary data (CC BY-SA) ·

"rationalism" is a 11-letter English headword indexed on PlainSpell.

The verdict

“rationalism” is a moderately-common English word, ranked #47,287 in English word frequency and used as a noun.

#47,287
frequency rank, English
11
letters
16
tracked misspellings
3
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The theory that reason is a source of knowledge independent of and superior to sense perception.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

rationalism vs rationality
82% similar
rationalism vs rationalize
82% similar
rationalism vs rationalist
91% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for rationalism
PropertyValue
Headwordrationalism
LanguageEnglish
Part of speechNoun
IPA/ˈɹæʃ(ə)nəlɪzəm/
Letters11
Frequency rank#47,287
Misspellings tracked16
Confusable pairs3
SourceWiktionary (kaikki.org)

Where “rationalism” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). rationalism lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for rationalism is 11 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈɹæʃ(ə)nəlɪzəm/. Corpus data places it at rank #47,287 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 4 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 16 likely wrong-spelling variants for rationalism, with forms such as "artionalism", "raitonalism", and "ratinoalism". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 3 confusable-pair relationships, "rationality", "rationalize", "rationalist", where similar look or sound leads writers to substitute one word for another in context.

Etymologically, the entry records: From rational + -ism. The correct English form is rationalism, spelled R-A-T-I-O-N-A-L-I-S-M.

Definition

  1. 1
    The theory that reason is a source of knowledge independent of and superior to sense perception.
  2. 2
    The theory that knowledge may be derived by deductions from a priori concepts (such as axioms, postulates or earlier deductions).
  3. 3
    A view that the fundamental method for problem solving is through reason and experience rather than faith, inspiration, revelation, intuition or authority.
  4. 4
    Elaboration of theories by use of reason alone without appeal to experience, such as in mathematical systems.

Etymology

From rational + -ism.

Synonyms

apriorismintellectualism

Antonyms

sensationalismirrationalismtraditionalismmysticism

This word in other languages

racionalismo(Español)rationalisme(Français)Rationalismus(Deutsch)

Common misspellings

Also misspelled as: artionalism,raitonalism,ratinoalism,ratioanlism,rationailsm,rationalims,rationalismm,rationalissm,rationallism,rationalsim,rationlaism,rationnalism,ratoinalism,rattionalism,rrationalism,rtaionalism

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of rationalism - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.

artionalism2raitonalism2ratinoalism2ratioanlism2rationailsm2rationalims2rationalismm1rationalissm1
Edit distance from "rationalism"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "rationalism"?
"rationalism" is spelled R-A-T-I-O-N-A-L-I-S-M. The IPA pronunciation is /ˈɹæʃ(ə)nəlɪzəm/.
What does "rationalism" mean?
As a noun, "rationalism" means: The theory that reason is a source of knowledge independent of and superior to sense perception.
What words are commonly confused with "rationalism"?
"rationalism" is commonly confused with "rationality", "rationalize", "rationalist". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "rationalism"?
The IPA (International Phonetic Alphabet) transcription for "rationalism" is /ˈɹæʃ(ə)nəlɪzəm/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "rationalism"?
From rational + -ism. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Using “rationalism”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is R-A-T-I-O-N-A-L-I-S-M - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈɹæʃ(ə)nəlɪzəm/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “rationality” - see the side-by-side comparison. rationalism vs rationality
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list