fastidious in WordNet English dictionary

1. having complicated nutritional requirements; especially growing only in special artificial cultures
   "fastidious microorganisms"; "certain highly specialized xerophytes are extremely exacting in their requirements"
   fastidious  exacting 
   
2. giving careful attention to detail; hard to please; excessively concerned with cleanliness
   "a fastidious and incisive intellect"; "fastidious about personal cleanliness"
   fastidious