operose

Operose comes from the Latin operōsus, which has the meaning of "diligent," "painstaking" or "laborious." That word combines opera, meaning "activity," "effort," or "work," with -ōsus—the Latin equivalent of the English -ose and -ous suffixes, meaning "full of" or "abounding in." In its earliest uses, in the mid-16th century, the word was used to describe people who are industrious or painstaking in their efforts. About a century later, the word was being applied as it more commonly is today: as an adjective describing tasks and undertakings requiring much time and effort.