Definition of assiduous
: showing great care, attention, and effort : marked by careful unremitting attention or persistent application <assiduous planning> <an assiduous book collector> <She tended her garden with assiduous attention.>
Examples of assiduous in a sentence
They were assiduous in their search for all the latest facts and figures.
The project required some assiduous planning.
The history of assiduous
Assiduous came to English directly from the Latin assiduus, an adjective derived from the verb assidēre "to sit beside." To the ancient Romans, assiduus carried meanings ranging from “settled or rooted in place” to “constantly present” to “persistent, unremitting." This last sense was the one borrowed into English four hundred years ago and still used today, often in complimentary phrases such as "an assiduous student" and “assiduous efforts.” In the 18th century, the word took on a mildly pejorative meaning, "obsequious," when used of someone striving to please. This sense has largely passed out of use.
Did You Know?
Judges presiding over assizes (former periodical sessions of the superior courts in English counties) had to be assiduous in assessing how to best address their cases. Not only were their efforts invaluable, but they also served as a fine demonstration of the etymologies of "assiduous," "assess," and "assize." All three of those words derive from the Latin verb assidēre, which is variously translated as "to sit beside," "to take care of," or "to assist in the office of a judge." "Assidēre," in turn, is a composite of the prefix ad- (in this case, meaning "near" or "adjacent to") and sedēre, meaning "to sit."
Origin and Etymology of assiduous
Latin assiduus, from assidēre to sit beside
First Known Use: circa 1552
Synonym Discussion of assiduous
ASSIDUOUS Defined for Kids
Definition of assiduous for Students
: showing great care, attention, and effort <They were assiduous in gathering evidence.>
Seen and Heard
What made you want to look up assiduous? Please tell us where you read or heard it (including the quote, if possible).