assiduous

[uh-sij-oo-uhs]

adjective

1. constant in application or effort; working diligently at a task; persevering; industrious; meticulous.

   an assiduous student.

   Synonyms: sedulous, diligent, studious
   Antonyms: lazy, inconstant

2. constant; unremitting.

   assiduous reading.

   Synonyms: persistent, tireless, continuous
   Antonyms: lazy, inconstant

assiduous

/ əˈsɪdjʊəs /

adjective

1. hard-working; persevering

   an assiduous researcher

2. undertaken with perseverance and care

   assiduous editing

Other Word Forms

• assiduously adverb
• assiduousness noun
• unassiduous adjective
• unassiduousness noun

Word History and Origins

Origin of assiduous¹

First recorded in 1530–40; from Latin assiduus, equivalent to assid(ēre) “to sit near or beside, dwell close to” ( assess ) + -uus adjective suffix; -ous

Word History and Origins

Origin of assiduous¹

C16: from Latin assiduus sitting down to (something), from assidēre to sit beside, from sedēre to sit

Example Sentences

A top-notch campus alone does not produce academic achievement — and, conversely, a brilliant teacher and an assiduous student in a one-room schoolhouse can make for an upstanding education.

Read more on Los Angeles Times

The drumbeat of criticism had spread to business leaders, including some of Trump’s most assiduous supporters in the billionaire and millionaire class.

Read more on Los Angeles Times

As the investigation spread across the globe, Ms Kierans said prosecutors realised McCartney had been "very assiduous about saving the images".

Read more on BBC

"Martyn is the most professional, assiduous, diligent police officer you will come across and he should never have been put in this position," he said.

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“I just feel like that assiduous pursuit of some level of truth sets her apart from a lot of people.”

Read more on Los Angeles Times

Related Words

• diligent 
• exacting 
• indefatigable 
• laborious 
• scrupulous 
• zealous