Libre
= Free as in freedom, as opposed to gratis (free of charge). The adjective implies all the freedoms associated with free software and libre resources: freedom to make copies, to modify and share unmodified or modified versions, and to use them for any purpose. [1]
Definition
"During the early years of the 21st century, the word "libre" acquired meaning in English, largely on account of the adoption of "FLOSS" as an accepted acronym for free/libre and open source software and common use of the term "software libre". "Libre" does not suffer the same ambiguity in the word "free" and many people prefer to say "libre knowledge". Nevertheless, the terms " free knowledge", "free culture" and "free content" are also widely used, and definitions have been posted on the Internet based on the free software definition." (http://wikieducator.org/Say_Libre)
More Information
Software Libre = Free Software