La palabra del día: Obligar

Verb. To move and impel to do or accomplish something, compel, bind. E.g.: El contrato obliga al proveedor a cumplir con los plazos de entrega: The contract compels the supplier to meet delivery times.
The nouns are la obligación and el obligamiento; the adjetives obligatorio/a and obligativo/a/s. They are interchangeable inside their own category but I prefer obligación and obligatorio/a/s. There is another noun: la obligatoriedad and it is applied to the quality of obligatorio/a/s. dc