A type of loan which isn't secured, or guaranteed, on the borrower's property 
Is a loan not backed up by collateral. 
most personal loans are "unsecured", meaning they do not require collateral.
A loan granted upon the good credit of the borrower. No collateral involved.
A loan where the lender has no entitlement to any of the borrower's assets in the event of the... <a target=_blank href='http://www.finance-glossary.com/terms/unsecured-loan.htm?id=1500&ginPtrCode=00000&PopupMode=false' title='Read full definition of unsecured loan'>more</a>
A loan that is not secured on property or goods.
An Unsecured Loan costs more in repayments than a Secured Loan, but does not carry the risks to your home if you unable to keep up repayments.