Under an obligation to do something. / Grateful or indebted because of a favor done.

simple past tense and past participle of oblige

(transitive) To constrain someone by force or by social, moral or legal means. / (transitive, intransitive) To do (someone) a service or favour (hence, originally, creating an obligation).

plural of obligation

One who, or that which, obliges.

Third-person singular simple present indicative form of oblige

present participle of obligate

One who binds themselves to another to pay or to perform something.

(law) One who establishes an obligation under law

plural of obligator