The term 'past due' is used to describe a situation in which something has not been paid or completed by the required date. The crossword solutions for this term are OWING (5 letters), LATE (4 letters), and NOTINTIME (9 letters). OWING refers to an amount of money that is owed, while LATE implies that something has not been done on time. NOTINTIME further emphasizes that something has not been done in the allotted time frame.