In English slang, talking double-dutch or Double Dutch means talking apparent nonsense or in in a confusing and contradictory way. The term may be used to describe a speech or policy statement so inconsistent or difficult to follow that a hearer/reader might say "it's all double-dutch to me". Holland used to a rival to England and the Dutch phrases were a form of a contempt.
It also means playing jump rope with two ropes and two people jumping simultaneously. There are at least two other people turning the ropes.