illogical

adjective

il·​log·​i·​cal (ˌ)i(l)-ˈlä-ji-kəl 

1

: not observing the principles of logic

an illogical argument

2

: devoid of logic : senseless

illogical policies

illogicality

(ˌ)i(l)-ˌlä-jə-ˈka-lə-tē 

noun

illogically

(ˌ)i(l)-ˈlä-ji-k(ə-)lē 

adverb

illogicalness

(ˌ)i(l)-ˈlä-ji-kəl-nəs 

noun

Synonyms

• fallacious
• illegitimate
• inconsequent
• inconsequential
• invalid
• irrational
• nonrational
• unreasonable
• unreasoning
• unsound
• weak

Examples of illogical in a Sentence

It is illogical to think that things will change on their own.

the illogical claim that playing basketball makes people taller because one sees so many tall players

Recent Examples on the Web

Second, this rationale for regulation proved to be illogical and fatuous as conceded by U.S. Courts and the Federal Communications Commission in the decades since. —Carine Harb, Newsweek, 9 Jan. 2025

Louis has to travel, and there’s the sense that Eva has nowhere else to go—a vague rationale that feels at once inevitable and illogical. —Chloe Schama, Vogue, 25 Dec. 2024

But although the play’s scenario certainly sets them up for banter, the dialogue itself is bizarrely unambitious and often illogical. —Helen Shaw, The New Yorker, 19 Sep. 2024

Honolulu’s case is illogical on its face given that its allegations of damages stem from interstate greenhouse gas emissions. —David Blackmon, Forbes, 30 Dec. 2024

Word History

First Known Use

1588, in the meaning defined at sense 1

Kids Definition

illogical

adjective

il·​log·​i·​cal (ˈ)il-ˈ(l)äj-i-kəl 

: not using or following good reasoning

illogically

-i-k(ə-)lē 

adverb