The word “Addendum” is a -

• Addendum - (noun) 
English Meaning: an item of additional material added at the end of a book or document, typically in order to correct, clarify, or supplement something.
Bangla meaning:
১) বাদ পড়েছে বলে যোগ করতে হবে এমন বস্তু
২) সংযোজন

Source: Bangla Academy Dictionary.