obligation obligation /ˌɑːbləˈgeɪʃən/

noun

1. () The social force that binds you to the courses of action demanded by that force  ( duty , obligation , responsibility )
   the social force that binds you to the courses of action demanded by that force
    We must instill a sense of duty in our children
   we must instill a sense of duty in our children
    Every right implies a responsibility; every opportunity, an obligation; every possession, a duty
   every right implies a responsibility; every opportunity, an obligation; every possession, a duty
   
2. () The state of being obligated to do or pay something  ( obligation )
   the state of being obligated to do or pay something
    He is under an obligation to finish the job
   he is under an obligation to finish the job
   
3. A legal agreement specifying a payment or action and the penalty for failure to comply  ( obligation )
   a legal agreement specifying a payment or action and the penalty for failure to comply
   
4. A written promise to repay a debt  ( certificate of indebtedness , debt instrument , obligation )
   a written promise to repay a debt
   
   
5. A personal relation in which one is indebted for a service or favor  ( indebtedness , obligation )
   a personal relation in which one is indebted for a service or favor