la-la

nonsense refrain in songs, probably from Old English la, a common exclamation; but la-la is imitative of babbling speech in many languages (cf. Greek lalage "babble, prattle," Sanskrit lalalla "imitation of stammering" Latin lallare "to sing to sleep, lull," German lallen "to stammer," Lithuanian laluoti "to stammer").

Online Etymology Dictionary, © 2010 Douglas Harper

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