interest-free
adjective
FINANCE ukusused to describe a loan with no extra payment in the form of interest:
The card offers 59 days' interest-free credit.
You are in effect getting an interest-free loan on 30% of your mortgage.
What happens when the interest-free period expires?
interest-free
adverb
FINANCE ukuswithout having to pay interest on a loan:
She lent them the money interest-free.