noun, noun which may take the genitive case particle 'no', adverb
every month; monthly; month by month
Used as a noun, adjectival modifier with の, or adverbially to describe something happening or being done each month.
家賃は月々5万円です。
The rent is 50,000 yen every month.
月々の支払い
Please don't forget the monthly payments.
会費は月々集めています。
We collect the membership fee month by month.