I was under the impression that it refered to the fact that gypsies turn up unexpectedly, stay for a while then disappear again just as unpredictably which is what the stream does, you never know if it will be flowing or not when you visit. The last few times I was up there there were indeed real gypsies camped along Burton Fleming Road just north of Rudston, literally on the other side of the road from the stream, which seemed rather apt. They had horses tethered up near Woldgate reservoir near South Side Mount barrow and were running two wheeled carts along Woldgate and Burton Agnes Balk. Unintentionaly they were probably recreating what you would have seen if you had stood up there in the Iron Age, not sure what the local attitude to it was but I enjoyed it.

-Chris