Adjustable-rate mortgage (ARM)
A mortgage or home equity loan in which your interest rate and monthly payments may change periodically during the life of the loan, based on the fluctuation of an index. Lenders may charge a lower interest rate for the initial period of the loan. Most ARMs have a rate cap that limits the amount the interest rate can change, both in an adjustment period, and over the life of the loan. Also called a variable-rate mortgage.