Lambda would be an assignable closure to a variable itself. Languages like PHP have allowed actual closures since about 5.2, and had create_function prior.
Here's a link for a quick breakdown of what we'll see in Java 8 (possibly): http://www.geekyarticles.com/2012/01...ct-lambda.html
Overall, I don't know why they would bother tbh. Methods can be retrieved by Reflection, so that's typically what I'd do anyway.