In a way that shows extreme care about details or an unwillingness to accept anything not perfect.
From 'fastidious' (the adjective) plus the adverbial suffix '-ly,' meaning to perform an action in a fastidious manner.
Scientists and surgeons often work fastidiously—their pickiness literally saves lives because tiny details matter when you're performing surgery or analyzing microscopic organisms!
Complete word intelligence in one call. Free tier — 50 lookups/day.