fastidious

Concise Oxford English Dictionary © 2008 Oxford University Press:
fastidious /faˈstɪdɪəs/

▶adjective

• 1 very attentive to accuracy and detail.

• 2 very concerned about cleanliness.

– derivatives
fastidiously adverb,
fastidiousness noun.

– origin ME (in the sense ‘distasteful’, later ‘disgusted’): from L. fastidiosus, from fastidium ‘loathing’.