From Latin fastīdiōsus, from fastīdium ("a loathing, aversion, disgust, niceness of taste, daintiness, etc."), perhaps for *fastutidium, from fastus ("disdain, haughtiness, arrogance, disgust") + taedium ("disgust").

• IPA: /fæˈstɪdi.əs/, /fəˈstɪdi.əs/

fastidious

1. Excessively particular, demanding, or fussy about details, especially about tidiness and cleanliness.

   Synonyms: exacting, fussy, meticulous, niggly, pernickety, Thesaurus:fastidious

   • 2003, Lynsay Sands, Single White Vampire:

     He had at first tried to clean up as they ate, his fastidious nature kicking in, but Chris had told him to just stop, he was blocking the TV.

   • 2004, Maria Osborne Perr, Ravished Wings‎:

     As she cleaned the room daily, she knew it was against his fastidious nature to bring or have food in his room.

   • 2008, Robert Fisher, Memory Road‎:

     His fastidious nature had been evident in his careful snipping of a customer's hair and now he guided his pencil with the same adroitness.

2. Overly concerned about tidiness and cleanliness.
3. Difficult to please; quick to find fault.
   • 1908, Henry James, The Portrait of a Lady (The Novels and Tales of Henry James), New York edition, volume (please specify |volume=I or II), Boston, Mass., New York, N.Y.: Charles Scribner's Sons, →OCLC ↗; republished as The Portrait of a Lady (EBook #283), United States: Project Gutenberg, 1 September 2001:

     You're too fastidious, and too indolent, and too rich.

   • 1897, Kate Chopin, The Lilies:

     "It's burn[t], M'sieur," said Marie Louise, politely, but decidedly, to the utter confusion of Mr. Billy, who was as mortified as could be at the failure of his dinner to please his fastidious little visitor.

4. (microbiology, of a microorganism) Having precise requirements for nutrition and environment (chemical and physical); especially, being difficult to culture because of those requirements.

   fastidious organism

   fastidious species

• French: pointilleux, minutieux
• German: anspruchsvoll, akribisch, kleinlich, manisch, minutiös, pedantisch, pingelig (colloquial), überkorrekt, wählerisch
• Italian: pignolo, meticoloso
• Portuguese: meticuloso, minucioso
• Russian: (излишне) тре́бовательный
• Spanish: cicatero, quisquilloso, regodeón

• French: méticuleux
• German: (colloquial) pingelig, penibel, übergenau, etepetete
• Italian: meticoloso, precisino
• Russian: брезгли́вый
• Spanish: maniático de la limpieza

• French: exigeant
• German: anspruchsvoll, wählerisch, kleinlich, mäkelig, zimperlich, eigen, heikel
• Portuguese: exigente
• Russian: прихотли́вый
• Spanish: exigente