Illogical

How to spell illogical

9 letters · 4 syllables

How to pronounce illogical

Say the part in capitals loudest.

What does illogical mean?

1. adjectiveLacking sound reasoning; contrary to the rules of clear, sensible thought.

Illogical in a sentence

• His refusal to look at the figures before deciding was completely illogical.

• It seems illogical to pay more for the smaller package.

Where does illogical come from?

Language of origin: Greek

This word is built on the Greek logos, which literally meant 'word' but came to carry the broader senses of 'reason', 'account', and 'principle of order'. From logos came logikos, 'concerning reasoning', which entered Latin as logicus and reached English through Old French as the noun and adjective 'logic'. The English adjective 'logical' was formed by adding the suffix -ical, and 'illogical' simply prefixes il-, an assimilated form of the negative in- ('not') that doubles the l before a root beginning with l, exactly as in 'illegal' and 'illegible'. That assimilation is the spelling trap: the word carries two l's at the start (il-) and another in the middle (log), so writers must remember the doubled opening. The word came into common use in the 1500s and 1600s, when English was busily borrowing and reshaping Latin and Greek vocabulary for academic and argumentative writing.

How the word is built

• il- (a form of in-, meaning 'not')
• log (from Greek logos: reason, word)
• -ical (adjective suffix)