Classified
来自Big Physics
Safin（讨论 | 贡献）2022年4月27日 (三) 14:54的版本 （建立内容为“Category:etymology == google == [https://www.google.com.hk/search?q=classified+etymology&newwindow=1&hl=en ref] late 18th century: back-formation from classi…”的新页面）
late 18th century: back-formation from classification, from French, from classe ‘class’, from Latin classis ‘division’.
wiktionary
classify + -ed
From classified advertisement, by shortening.
etymonline
classified (adj.)
1828, "arranged in classes," past-participle adjective from classify. Meaning "secret" (in reference to government information) is from 1941, American English. Classifieds (n.) "newspaper advertisements arranged by classes," 1913, is short for classified advertisements
