The word “assiduous” — meaning “showing great care” — is most often used today to describe someone with hardworking attention to detail. For example, someone with impeccable organizational skills could be praised as assiduous. The root of the word comes from the Latin “assidere,” which means “be engaged in doing,” but there’s another connotation of the Latin word, which is “to sit by.” While this usage seems at odds with the industriousness of “assiduous,” it’s also the etymological root of the English word “assess.” The words are connected, as it’s hard to be productive without first assessing the situation.