definition of
fastidious

[1] #1 fastidious a. giving careful attention to detail; hard to please; excessively concerned with cleanliness; "a fastidious and incisive intellect"; "fastidious about personal cleanliness". wn

[2] #2 fastidious a. [exacting] having complicated nutritional requirements; especially growing only in special artificial cultures; "fastidious microorganisms"; "certain highly specialized xerophytes are extremely exacting in their requirements". wn