Lien-free is a term used for a property that is owned outright by an individual(s), listing that individual(s) on the title as the registered owner. There is no outstanding loan obligation on a lien-free property.
http://www.hjventures.com/payday-loans/lien-free.html
Lien

A right given to another by the owner of property to secure a debt, or one created by law in favor of certain creditors.

A lien is an encumbrance on one person's property to secure a debt the property owner owes to another person. The statement that someone's property is "tied up" describes the effect of liens on both real and Personal Property. Lien is a French word meaning "knot or binding" that was brought to Britain with the French language during the Norman Conquest in 1066.
http://legal-dictionary.thefreedictionary.com/lien