Just for kicks I went to wikipedia. I honestly expected to find a jargon-filled and useless definition, but was pleasantly surprised. I think they have a decent definition.

"In software development, a Framework is a defined support structure in which another software project can be organized and developed. Typically, a framework may include support programs, code libraries and a scripting language amongst other software to help develop and glue together the different components of your project. "
Source: http://en.wikipedia.org/wiki/Framework

- jbWare