assiduous

American  

[uh-sij-oo-uhs] / əˈsɪdʒ u əs /

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

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assiduous British  

/ əˈsɪdjʊəs /

adjective

1. hard-working; persevering

   an assiduous researcher

2. undertaken with perseverance and care

   assiduous editing

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Other Word Forms

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

Etymology

Origin of assiduous

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

Explanation

If you call someone assiduous, it's a compliment. It means they're careful, methodical and very persistent. Good detectives are classically assiduous types. Assiduous comes from two Latin words: assiduus, meaning "busy incessant, continual or constant," and assidere, meaning "to sit down to" something. (Funnily enough, we also get the word sedentary, meaning someone who doesn't move around much, a lazy couch potato, from this same last word.) Although we tend to think of sedentary types as being the very opposite of assiduous ones, many assiduous activities (like writing, thinking, or detective work) are best done sitting in a chair.

Example Sentences

Assiduous work improved the engine's reliability and, by 1979, the team also had a competitive chassis.

From BBC • Feb. 2, 2023

Assiduous with his diet, yoga, training and recovery regimen, Djokovic has forged his 6-foot-2, 170-pound frame into a model of continuous improvement.

From Washington Post • Jan. 29, 2023

Assiduous fund raising and sound investing had built its endowment to $209 million; money was literally coming in faster than it could be spent.

From Time Magazine Archive

Assiduous men roam the world, in large groups and small, to uncover forgotten things in old places freshly found.

From Time Magazine Archive

The Assiduous Angler.—The constant-in-application man becomes the practical fisherman.

From The Determined Angler and the Brook Trout an anthological volume of trout fishing, trout histories, trout lore, trout resorts, and trout tackle by Bradford, Charles Barker

Related Words

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