2、来自PIE*dhel, 空的，词源同dell. 引申义峡谷。
2、dale: [OE] Both dale and dell [OE] come ultimately from the Germanic base *dal- (which also produced German tal, ultimate source of English dollar). Dale goes back to the Germanic derivative *dalam, *dalaz, dell to the derivative *daljō. Cognate forms such as Old Norse dalr ‘bow’ and, outside Germanic, Greek thólos show that the underlying meaning of the word family is ‘bend, curve’. Those members which mean ‘valley’ (including Gothic dals, which also signified ‘ditch’) were no doubt named from their rounded, hollowed-out shape.=> dell, dollar
4、Old English dæl"dale, valley, gorge,"from Proto-Germanic *dalan"valley"(cognates: Old Saxon, Dutch, Gothic dal, Old Norse dalr, Old High German tal, German Tal"valley"), from PIE *dhel-"a hollow"(cognates: Old Church Slavonic dolu"pit,"Russian dol"valley"). Preserved by Norse influence in north of England.