Definitions
1.adjective(of a person) Late, tardy, overdue, behind (in accomplishing a task, etc.).
2.adjective(of a task or the object of a task) Not at the expected point of completion.
3.adjectiveBehind (someone or something moving, a trend, etc.), lagging behind, not keeping up.
4.adjectiveBehind in paying a debt; in arrears.
5.adjectiveNot having enough of, lacking (in something).
6.adjectiveInferior, less advanced (compared with someone in something).
7.adverbBelatedly, tardily.
8.adverbIn debt, or in arrears.