fas ‧ tid ‧ i ‧ ous /fæˈstɪdiəs/ BrE AmE adjective
[ Date: 1400-1500 ; Language: Latin ; Origin: fastidiosus , from fastidium 'strong dislike' ]
very careful about small details in your appearance, work etc SYN meticulous :
people who are fastidious about personal hygiene
—fastidiously adverb
—fastidiousness noun [uncountable]