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

This is not to impugn the nobility of counting, of the close and careful observation of nature, of the rational, ordered efforts to understand it. — Literary Hub, 22 Sep. 2026

The fact, in other words, that there often isn’t a right answer or a clear victor—and that rational people are subject to irrational forces within and above them. — Max Norman, Harpers Magazine, 22 Sep. 2026

Mathematicians have long known that some polynomial equations have only rational solutions, while others have irrational solutions (such as ). — Lyndie Chiou, Scientific American, 22 Sep. 2026

The ballroom, however, almost seems like a rational investment compared with the arch that Trump wants to build in front of America’s most hallowed ground. — Tom Nichols, The Atlantic, 20 Sep. 2026