2. It can also mean someone who constantly bullshits without any luck through over-hyped, often far fetched, distorted statements which is 'winged' through social circles without any regard for his/her personal credibility thus giving other people impressions of him being a constant liar or a person who cannot be trusted.
4. Common fallacy
"Never trust a person like Wayne because he is simply a wing yuen"
"That play was not even that good. It's just been wing yuened by that guy over the last couple of days"