dip: [OE] Like deep, dip comes ultimately from a Germanic base *d(e)up- ‘deep, hollow’. The derived verb, *dupjan, produced Old English dyppan, ancestor of modern English dip. It originally meant quite specifically ‘immerse’ in Old English, sometimes with reference to baptism; the sense ‘incline downwards’ is a 17th-century development. => deep, dimple[dip etymology, dip origin, 英语词源]