- The definition of obligatory is necessary, required or expected as a result of law or social custom.
- When someone waves at you and you feel like you have to wave back because social system says you do in order to be polite, the return wave is an example of an obligatory wave.
- When the law requires you to stop at a red light, this is an example of a time when stopping is obligatory.
obligatory definition by Webster's New World
- legally or morally binding; constituting, or having the nature of, an obligation; required
- Biol. obligate
Origin: Late Latin obligatorius
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
- obligatorily adverb
obligatory definition by American Heritage Dictionary
- Morally or legally constraining; binding.
- Imposing or recording an obligation: a bill obligatory.
- Of the nature of an obligation; compulsory: Attendance is obligatory. Mathematics is an obligatory course.
- Biology Obligate.
- o·bligˌa·toˈri·ly adverb