1650s, intransitive, "to idle, waste time," perhaps a variant of daddle "to walk unsteadily." Perhaps influenced by daw, because the bird was regarded as sluggish and silly. Not in general use until c. 1775. Transitive sense in dawdle away is attested by 1768. Related: Dawdled; dawdling; dawdler.
updated on June 30, 2018