fas·​tid·​i·​ous fa-ˈsti-dē-əs How to pronounce fastidious (audio)
of a person's work, approach, etc. : extremely or excessively careful or detailed
fastidious research
scenes drawn in fastidious detail
… he took fastidious care of his cars.Marga Lincoln
… his fastidious approach to tasks—making detailed, several-page lists on yellow pads …Josh Dawsey et al.
… her fastidious—but never fussy—prose …Kirkus Reviews
But many food poisoning outbreaks are complicated. Some are never solved. Cracking them is fastidious work.Lynne Terry
Just as famous was the 1965 Jaguar [guitar] he played, which Fender has recreated with fastidious attention to
of a person or trait : characterized by a meticulous, sensitive, or demanding attitude
a fastidious dresser/eater
… a collector with fastidious taste.Martin Chulov
True to her fastidious nature, Peretti hand-selected all of the stones included in the collections …Misty White Sidell
: such as
: having high and often capricious standards
… critics … so fastidious that they can talk only to a small circle of initiates.Granville Hicks
: characterized by extreme or excessive concern about cleanliness or neatness
a fastidious housekeeper
But in the hazy panic of the time, many people had already taken up fastidious habits: quarantining packages at the door, bleaching boxes of cereal brought back from the store, wearing hospital booties outdoors.Gregory Barber
Disorder and dirt filled the rough cabin, or so it seemed to her fastidious eye.William MacLeod Raine
: having complex nutritional requirements
fastidious microorganisms
archaic : scornful
fastidiously adverb
fastidiousness noun

Did you know?

Fastidious Has a Disgusting Past

Fastidious comes from Latin fastidium, meaning "aversion" or "disgust." Fastidium is believed to be a combination of fastus, meaning "arrogance," and taedium, "irksomeness" or "disgust." (Taedium is also the source of tedium and tedious.) In keeping with its Latin roots, fastidious once meant "haughty," "disgusting," and "disagreeable," but the word is now most often applied to people who are very meticulous or overly difficult to please, or to work which reflects a demanding or precise attitude.

Examples of fastidious in a Sentence

My mother had always been the most fastidious and organized of people—a wet ring left on her coffee table by a glass could drive her to distraction. John B. Judis, New Republic, 14 Oct. 1996
"I'll stop off and get us a sandwich," said Matthew.  … Tony, a fastidious eater, sighed. Penelope Lively, City of the Mind, 1991
Though he prides himself on being hip, he is too fastidious to do anything dangerous or dirty. Jay McInerney, Bright Lights, Big City, 1984
He is fastidious about keeping the house clean. She was too fastidious to do anything that might get her dirty.
Recent Examples on the Web Much like her character, the fastidious manager who wants to ensure impeccable experiences for her guests, Impacciatore always kept her wardrobe crisp and tucked-in. Karen M. Peterson, Variety, 13 Aug. 2023 Like a tree grows in Brooklyn, a pennant shop grows again in Buffalo, thousands upon thousands of pieces each year running through the hands of the fastidious sewers on the second floor at 810 Main St. Kevin Paul Dupont,, 12 Aug. 2023 Being the fastidious performer Reubens was, it simply couldn’t be done to his standards on a regular basis with the kind of budget the station had to work with. Chris Eggertsen, Billboard, 1 Aug. 2023 With fastidious research on underwater archaeology and the many life forms that inhabit the sea floor and thrilling accounts of her own descents to the deep, Casey's book satisfies our greatest curiosities about the mysteries of the ocean. Time, 31 July 2023 Most of us don’t reach our opinions by fastidious calibration of empirical evidence. David Quammen, New York Times, 25 July 2023 The fastidious formality of Monsieur Gustave H. exists right alongside his matter-of-fact vulgarity, a combination that Fiennes nails with astounding precision. Joe Reid, Vulture, 26 June 2023 Lanny Breuer, the assistant attorney general who was Smith's boss at the Justice Department, described him as a completely apolitical prosecutor who is fastidious in his investigations, and impervious to pressure. Josh Meyer, USA TODAY, 28 July 2023 Especially coming from a studio that used to be so terrifyingly fastidious about its world-building, the internal logic of Element City is wobbly at best—e.g., Ember can burn instantly through a chain-link fence but can sit safely in a movie-theatre seat. Jessica Winter, The New Yorker, 22 June 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'fastidious.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English, from Latin fastidiosus, from fastidium disgust, probably from fastus arrogance (probably akin to Latin fastigium top) + taedium irksomeness — more at tedium

First Known Use

15th century, in the meaning defined at sense 3

Time Traveler
The first known use of fastidious was in the 15th century


Dictionary Entries Near fastidious

Cite this Entry

“Fastidious.” Dictionary, Merriam-Webster, Accessed 4 Oct. 2023.

Kids Definition


fas·​tid·​i·​ous fa-ˈstid-ē-əs How to pronounce fastidious (audio)
: hard to please : very particular
fastidiously adverb
fastidiousness noun

Medical Definition


fas·​tid·​i·​ous fa-ˈstid-ē-əs, fə- How to pronounce fastidious (audio)
: having complex nutritional requirements
fastidious microorganisms
used of bacteria that grow only in specially fortified artificial culture media

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