"Free" is an Archetypal idea, which is to say a layered complexity with conscious and unconscious elements and no ultimate beginning or end; a weave of ideas experienced and shaped by many human beings which allows simultaneous contact with more related meanings than any one person can manage.
to free (transitive) To make free; set at liberty; release; rid of that which confines, limits, embarrasses, or oppresses.
free Not imprisoned or enslaved. Obtainable without payment. Unconstrained. Unobstructed, without blockages. Not in use. Without obligations. As in software, having very few limitations on distribution or improvement. Without; not containing (what is specified).
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See http://en.wiktionary.org/wiki/free