Dictionary.com
Thesaurus.com
Synonyms

diligent

American  
[dil-i-juhnt] / ˈdɪl ɪ dʒənt /

adjective

  1. constant in effort to accomplish something; attentive and persistent in doing anything.

    a diligent student.

    Synonyms:
    sedulous, assiduous, industrious
  2. done or pursued with persevering attention; painstaking.

    a diligent search of the files.

    Synonyms:
    unremitting, tireless, indefatigable

diligent British  
/ ˈdɪlɪdʒənt /

adjective

  1. careful and persevering in carrying out tasks or duties

  2. carried out with care and perseverance

    diligent work

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Synonym Usage

See busy.

Other Word Forms

Etymology

Origin of diligent

First recorded in 1300–50; Middle English, from Anglo-French or directly from Latin dīligent- (stem of dīligēns ), present participle of dīligere “to choose, like,” equivalent to dī- di- 2 + -ligere (combining form of legere “to choose, read”); see -ent

Compare meaning

How does diligent compare to similar and commonly confused words? Explore the most common comparisons:

Explanation

Someone who is diligent works hard and carefully. If you want to write the epic history of your family, you'll have to be very diligent in tracking down and interviewing all of your relatives. Diligent comes from the Latin diligere, which means "to value highly, take delight in," but in English it has always meant careful and hard-working. If you're a diligent worker, you don't just bang away at your job; you earnestly try to do everything right. Although being lucky and talented doesn't hurt, it's the diligent person who eventually succeeds.

Keep Reading on Vocabulary.com

Vocabulary lists containing diligent

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

“Even the most diligent and responsible pet owner can experience the unexpected,” Oreck said.

From Los Angeles Times Jul. 3, 2026

In other cases, diligent taxpayers file extensions because they don’t have all the forms they need.

From MarketWatch Jun. 8, 2026

She was a dedicated observer of the Sabbath and Jewish laws, a diligent student of Hebrew and a tireless philanthropic force in aiding vulnerable Jewish communities abroad.

From The Wall Street Journal Jun. 7, 2026

"Luckily the keepers here are incredibly diligent, so they are noticing the subtle changes in an animal."

From BBC Apr. 21, 2026

When David Shoun was questioned, he conceded that there was no exit wound, but he insisted that he and his brother had “made a diligent search” for the bullet.

From "Killers of the Flower Moon" by David Grann

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training