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

Which was probably to be expected, given that making a new entry in this franchise doesn’t require jumping through too many illogical hoops or reinventing an outdated conceit. —Bilge Ebiri, Vulture, 16 May 2025

His insight and unconventional approach to understanding human behavior lead him and the team on a series of intense, unexpected journeys to solve illogical puzzles and perplexing mysteries. —Nellie Andreeva, Deadline, 9 May 2025

Life gets weird sometimes — fickle, illogical, dreamlike. —Leslie Katz, Forbes.com, 8 May 2025

Pike’s stairs, however, are an M.C. Esher–esque illogical maze, full of steep drop-offs and impossible turns. —Rebecca Alter, Vulture, 29 Apr. 2025

Word History

First Known Use

1588, in the meaning defined at sense 1

Rhymes for illogical

• zoological
• aetiological
• anthropological
• archaeological
• axiological
• climatological
• deontological
• dermatological
• eschatological
• etiological
• etymological
• gerontological

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