fastidious

UK: /fæˈstɪdiəs/ US: /fæˈstɪdiəs/ ,(fa stid′ē əs, fə-)

WordReference Random House Learner's Dictionary of American English © 2025

fas•tid•i•ous /fæˈstɪdiəs/   adj. 

1. overly particular, critical, or demanding;
   hard to please:
   a fastidious eater.
2. requiring or having excessive care or delicacy:
   fastidious attention to detail.

fas•tid•i•ous•ly, adv. 
fas•tid•i•ous•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2025

fas•tid•i•ous  (fa stid′ē əs, fə-), adj. 

1. excessively particular, critical, or demanding;
   hard to please:
   a fastidious eater.
2. requiring or characterized by excessive care or delicacy;
   painstaking.

• Latin fastīdiōsus squeamish, equivalent. to fastīdi(um) lack of appetite, disgust, perh. by syncope of *fastutīdium (fastu-, combining form of fastus pride, conceit + -tīdium combining form of taedium tedium) + -ōsus -ous
• late Middle English 1375–1425

fas•tid′i•ous•ly, adv. 
fas•tid′i•ous•ness, n. 
Synonyms

• 1. See particular. 

Collins Concise English Dictionary © HarperCollins Publishers::

fastidious / fæˈstɪdɪəs/ adjective

1. very critical; hard to please
2. excessively particular about details
3. exceedingly delicate; easily disgusted

Etymology: 15th Century: from Latin fastīdiōsus scornful, from fastīdium loathing, from fastus pride + taedium weariness

fasˈtidiously adverb

fasˈtidiousness noun