Invalid
Invalid adjective - Having no basis in reason or fact.
Usage example: an invalid claim that can be easily disproved by the facts
Illogical is a synonym for invalid in correct topic. In some cases you can use "Illogical" instead an adjective "Invalid", when it comes to topics like worthless, null and void, unfounded. popular alternative
Illogical
Illogical adjective - Not using or following good reasoning.
Usage example: illogical people are likely to believe every sensational claim made on TV
Invalid is a synonym for illogical in correct topic. You can use "Invalid" instead an adjective "Illogical", if it concerns topics such as irrational, null and void, incorrect, not making sense. popular alternative
Nearby Word: illogicality
Mutual synonyms
Related pairs
Cite this Source
Illogical and Invalid. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/invalid/illogical
Invalid & Illogical. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/invalid/illogical>.
Illogical or Invalid. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/invalid/illogical.
Google Ngram Viewer shows how "invalid" and "illogical" have occurred on timeline