toutyoudaoicibaDictYouDict[tout 词源字典]
tout: [14] The etymological notion underlying tout is of ‘sticking out, projecting’. It goes back ultimately to the prehistoric Germanic base *tūt- ‘project’, whose other descendants include Dutch tuit ‘spout’. It is assumed to have produced an Old English *tūtian, but it does not turn up in the written record until the Middle English period, by which time the notion of ‘poking out’ had moved on to ‘peeking’ or ‘peeping’. It progressed further to ‘spy on’, but the modern ‘look for business’ did not emerge until the 18th century.
[tout etymology, tout origin, 英语词源]
peek (v.)youdaoicibaDictYouDict
late 14c., piken "look quickly and slyly," of unknown origin. The words peek, keek, and peep all were used with more or less the same meaning 14c.-15c.; perhaps the ultimate source was Middle Dutch kieken. Related: Peeked; peeking.