Obligation
Obligation noun - Something one must do because of prior agreement.
Usage example: their financial obligations keep them from giving to charities as much as they would like
Option is an antonym for obligation.
Option
Option noun - The power, right, or opportunity to choose.
Usage example: you will have the option to select one of several quite different health insurance plans
Obligation is an antonym for option.
How words are described
Cite this Source
Option and Obligation. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/obligation/option
Obligation & Option. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/obligation/option>.
Option or Obligation. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/obligation/option.
Google Ngram Viewer shows how "obligation" and "option" have occurred on timeline