English Etymology From over- + diligent. Adjective overdiligent (comparative more overdiligent, superlative most overdiligent) Too diligent. 1906, Life, volume 48, page 10:Diligent in business our people will be and must be, but not overdiligent. Translations Translations Finnish: liian tunnollinen, liian huolellinen German: überfleißig Polish: zbyt pilny Wikiwand - on Seamless Wikipedia browsing. On steroids.