Cardinal
Cardinal adjective - Coming before all others in importance.
Usage example: the cardinal rule of medicine: do no harm
Key is a synonym for cardinal in important topic. In some cases you can use "Key" instead the word "Cardinal" as an adjective or a noun, when it comes to topics like property, principal, fundamental, basic. popular alternative
Nearby Words: cardinally, cardinality
Key
Key adjective - Coming before all others in importance.
Usage example: maintains that Sir Isaac Newton remains the key figure in physical science
Cardinal is a synonym for key in property topic. You can use "Cardinal" instead the word "Key" as an adjective or a noun, if it concerns topics such as important, fundamental, basic. popular alternative
Mutual synonyms
Cite this Source
Key and Cardinal. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/cardinal/key
Cardinal & Key. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/cardinal/key>.
Key or Cardinal. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/cardinal/key.
Google Ngram Viewer shows how "cardinal" and "key" have occurred on timeline