early 15c., "a vote to choose someone to decide a question," from Late Latin scrutinium "a search, inquiry" (in Medieval Latin, "a mode of election by ballot"), from Latin scrutari "to examine, investigate, search," from PIE root *skreu- "to cut; cutting tool" (see shred, n.). Meaning "close examination" first recorded c.1600. Perhaps the original notion of the Latin word is "to search through trash," via scruta (plural) "trash, rags" ("shreds"); or the original sense might be "to cut into, scratch."