Very attentive to and concerned about accuracy and detail. She was fastidious about her work, ensuring every detail was perfect.
Very concerned about matters of cleanliness. He was fastidious in his personal hygiene, never leaving the house without a shower.
Hard to please; excessively particular or demanding. The toddler was fastidious, refusing to eat any food that was not cut into perfect squares.
Requiring specific, often complex nutritional or environmental conditions for growth (used especially of microorganisms). The bacterium is fastidious, thriving only on enriched media.