Merriam-Webster's Collegiate® Dictionary, 11th Edition
DUE
I. adjective see: debt
Date: 14th century
owed or owing as a debt,
2. owed or owing as a natural or moral right , according to accepted notions or procedures ; appropriate ,
3. satisfying or capable of satisfying a need, obligation, or duty ; adequate , regular , lawful , capable of being attributed ; ascribable, having reached the date at which payment is required ; payable , required or expected in the prescribed, normal, or logical course of events ; scheduled , dueness noun
II. noun
Date: 15th century
something due or owed: as, something that rightfully belongs to one , a payment or obligation required by law or custom ; debt , fees, charges ,
III. adverb
Date: 1582
directly , exactly , duly