The legal definition of mechanic’s lien is a security interest in the title to property for the benefit of those who have supplied labor or materials that improve the property. The lien exists for both real property and personal property. In layman’s terms, a mechanic’s lien means that at some point in the past an individual or company performed work on the house (paint, roof, etc.) but was never paid, so they filed a lien with the courts that attached to the property so they would have to be paid before the property could be sold. Mechanic’s liens have thrown a monkey wrench into many deals. Here’s the 411 on mechanic’s liens and how to avoid getting tripped up by one.