Synonyms of rational

rational

adjective

ˈrash-nəl 

1

as in intelligent

having the ability to reason

human beings are rational creatures

Synonyms & Similar Words

• intelligent
• reasoning
• reasonable
• thinking
• logical
• mental
• analytic
• intellectual
• practical
• cognitive
• cerebral
• sensible
• sane
• brainy
• cognitional
• highbrow
• levelheaded
• highbrowed
• sober

Antonyms & Near Antonyms

• irrational
• unreasonable
• nonrational
• unthinking
• unintelligent
• unreasoning
• stupid
• dense
• slow
• dumb
• mindless
• dull
• senseless
• fatuous
• obtuse
• nonthinking
• brainless
• illogical
• dopey
• nonsensical
• dorky
• groundless
• fallacious
• invalid
• doltish
• thickheaded
• half-witted

2

as in logical

according to the rules of logic

insisted there was a rational explanation for the strange creaking noises and that there were no such things as ghosts

Synonyms & Similar Words

• logical
• reasonable
• coherent
• valid
• sensible
• good
• analytic
• empirical
• sound
• justifiable
• consequent
• well-grounded
• well-founded
• cognitive
• defensible
• syllogistic
• sustainable
• a priori
• supportable
• tenable
• maintainable
• a posteriori
• defendable

Antonyms & Near Antonyms

• irrational
• unreasonable
• illogical
• weak
• incoherent
• unsound
• illegitimate
• misleading
• invalid
• inconsequential
• specious
• sophistic
• fallacious
• casuistic
• unscientific
• inconsequent
• stupid
• absurd
• unarticulated
• insane
• mad
• nonsensical
• crazy
• preposterous
• eristic
• fatuous
• loony
• nutty
• thoughtless
• witless
• senseless
• simpleminded
• daffy
• harebrained
• cockeyed
• unconvincing
• weak-minded
• half-baked
• half-witted
• uncompelling

3

as in reasonable

based on sound reasoning or information

betting all of your savings on the lottery is not a rational move

Synonyms & Similar Words

• logical
• reasonable
• reasoned
• sensible
• valid
• good
• justified
• solid
• hard
• true
• commonsense
• informed
• sober
• plausible
• well-founded
• commonsensical
• levelheaded
• firm
• credible
• just
• real
• actual
• validated
• commonsensible
• convincing
• certain
• sure
• substantiated
• cogent
• certified
• confirmed
• colorable
• verified
• corroborated

Antonyms & Near Antonyms

• irrational
• unreasonable
• illogical
• nonrational
• unsound
• nonsensical
• uninformed
• unfounded
• unjustified
• groundless
• invalid
• unwarranted
• unsupported
• unsubstantiated
• unreasoned
• weak
• implausible
• flimsy
• unconvincing
• false
• misguided
• nonvalid
• fallacious
• misled

Example Sentences

Recent Examples of rational

Defense can’t be too timid, but there needs to be rational response to an asymmetric downside. — Bob Ackerman, Forbes.com, 6 Oct. 2026

Humans, in contrast, have souls that are additionally capable of rational thought. — Encyclopedia Britannica, 30 Sep. 2026

From the inside looking out, though, the perspective was considerably more rational and upbeat. — Kansas City Star, 27 Sep. 2026

Founded by two British academics almost two decades ago, Effective Altruism is a philosophical movement whose core idea is that people should try to use rational processes to do the most good for the most people in the world. — Beatrice Nolan, Fortune, 23 Sep. 2026