dumbwaiter (n.)youdaoicibaDictYouDict[dumbwaiter 词源字典]
1749, an article of furniture, from dumb (adj.) + waiter (apparently because it serves as a waiter but is silent). As a movable platform for passing dishes, etc., up and down from one room (especially a basement kitchen) to another, from 1847.[dumbwaiter etymology, dumbwaiter origin, 英语词源]