saladyoudaoicibaDictYouDict[salad 词源字典]
salad: [15] Etymologically, a salad is a ‘salted’ dish. The word comes via Old French salade from Vulgar Latin *salāta, a noun use of the feminine past participle of Latin *salāre ‘put salt on to, treat with salt’. This is turn was a derivative of sāl ‘salt’, a relative of English salt. The Romans were fond of dishes of assorted raw vegetables with a dressing, and this often consisted of brine – hence the name, which is short for herba salāta ‘salted vegetables’.
=> salt[salad etymology, salad origin, 英语词源]
salad (n.)youdaoicibaDictYouDict
late 14c., from Old French salade (14c.), from Vulgar Latin *salata, literally "salted," short for herba salata "salted vegetables" (vegetables seasoned with brine, a popular Roman dish), from fem. past participle of *salare "to salt," from Latin sal (genitive salis) "salt" (see salt (n.)).

Dutch salade, German Salat, Swedish salat, Russian salat are from Romanic languages. Salad days "time of youthful inexperience" (perhaps on notion of "green") is first recorded 1606 in Shakespeare and probably owes its survival, if not its existence, to him. Salad bar first attested 1940, American English.