English to Greek Other Other Ornithology technical term

Means descending rapidly from a height once the decision to land has been made, involving fast side-slipping first one way and then the other. The term is usually applied to geese (Anatidae), whose flocks whiffle spectacularly, especially when wishing to avoid a long, slow descent over an area where wildfowling is practised. It results in an aerial manoeuvre in which a bird flies with its neck twisted 180 degrees and its body upside down in order to achieve a rapid yet controlled descent. See further:-
http://www.dailymail.co.uk/news/article-1184566/Whiffle-wind...