obligation-n; 3 Senses

Sense Number 1: The social force that binds one to the courses of action demanded by that force.

Commentary: OBLIGATION[+social]

Examples:
Every opportunity implies an obligation.
Rights and obligations rule the world.

Mappings:
WordNet 3.0 Sense Numbers: 1

Sense Number 2: The state of being obligated to do or pay something (to someone else).

Commentary: OBLIGATION[+relation][+event]

Examples:
He made an obligation to pay Caesar back.
He is under an obligation to finish the job.

Mappings:
WordNet 3.0 Sense Numbers: 2, 3

Sense Number 3: The written document that promises to repay a social or financial debt.

Commentary: OBLIGATION[+artifact]

Examples:
He tore the obligation to shreds.
We wrote the obligation yesterday.

Mappings:
WordNet 3.0 Sense Numbers: 4, 5