verb · 9 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
General-American:/ˈɹæʃənəlaɪz/
Southern-England:Recorded audio is listed in the source snapshot.
CMU ARPABET:R AE1 SH AH0 N AH0 L AY2 Z
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
verb
Meaning 1
To make something rational or more rational.
Definition source: English Wiktionary via Wiktextract
Usage: British, English, Oxford, US
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
verb
Meaning 2
To justify a discreditable act, or irrational behaviour.
Definition source: English Wiktionary via Wiktextract
Usage: British, English, Oxford, US
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
verb
Meaning 3
To remove radicals, without changing the value of an expression or the roots of an equation.
Definition source: English Wiktionary via Wiktextract
Usage: British, English, Oxford, US
Topics: mathematics, sciences
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
verb
Meaning 4
To structure something along modern, efficient and systematic lines, or according to scientific principles. This often includes eliminating duplication and grouping like or similar items.
Definition source: English Wiktionary via Wiktextract
Usage: British, English, Oxford, US
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
5
verb
Meaning 5
weed out unwanted or unnecessary things
Definition source: Princeton WordNet 3.0
Examples
We had to lose weight, so we cut the sugar from our diet
Meaning relationships
Synonyms: cut, prune, rationalise
Antonyms: none provided
Broader terms: extinguish, eliminate, get rid of, do away with
6
verb
Meaning 6
remove irrational quantities from
Definition source: Princeton WordNet 3.0
Examples
This function can be rationalized
Meaning relationships
Synonyms: rationalise
Antonyms: none provided
Broader terms: change, alter, modify
7
verb
Meaning 7
think rationally; employ logic or reason
Definition source: Princeton WordNet 3.0
Examples
When one wonders why one is doing certain things, one should rationalize
Meaning relationships
Synonyms: rationalise
Antonyms: none provided
Broader terms: think, cogitate, cerebrate
8
verb
Meaning 8
defend, explain, clear away, or make excuses for by reasoning