A really annoying noise that you make by putting your lips together and blowing air out, when one first learns how to do it, the noise does not sound like a bird, but when they master it the bird call can sound like a bird.
a screeching sound made by a person when they are mad or being annoyed by something or someone.
usually attracts attention and makes you look like you have a mental disability but it is a good way of telling someone that you hate them. in more of a friendly matter.