First Lien
A lien is a claim or legal right of a creditor or lender to seize an asset if the borrower fails to pay off the contract. It serves to guarantee an underlying obligation, such as the repayment of a loan. The first lien has priority over all other secondary liens, or claims, on an asset.
In real estate, the first lien is generally the first mortgage on a property. If the homeowner fails to pay their mortgage, the lien empowers the lender to take possession of the property in order to recoup the debt.
More information on liens here.