sherlock

the verb 'sherlock' is an eponym derived from the fictional detective sherlock holmes, created by sir arthur conan doyle in the late 19th century. the character's name itself is of old english origin, likely meaning "fair-haired" or "bright-haired" from elements meaning "shire" (bright) and "locc" (lock of hair). through the immense popularity of the stories, the name became synonymous with brilliant, deductive investigation. by the early 20th century, it underwent conversion, entering the language as a verb meaning to investigate or deduce in a masterful manner, exemplifying how a proper noun can lexicalize into a common verb based on cultural archetypes.

this is a proper noun converted into a verb (eponym). it is not composed of productive morphemes in modern english.