obligatory

[uh-blig-uh-tawr-ee, -tohr-ee, ob-li-guh-]

adjective

1. required as a matter of obligation; mandatory.

   A reply is desirable but not obligatory.

2. incumbent or compulsory (usually followed by on orupon ).

   duties obligatory on all.

   Synonyms: imperative, necessary
   Antonyms: voluntary

3. imposing moral or legal obligation; binding.

   an obligatory promise.

4. creating or recording an obligation, as a document.

obligatory

/ ɒˈblɪɡətərɪ, -trɪ /

adjective

1. required to be done, obtained, possessed, etc

2. of the nature of or constituting an obligation

Other Word Forms

• obligatorily adverb
• obligatoriness noun
• nonobligatorily adverb
• nonobligatory adjective
• unobligatory adjective

Word History and Origins

Origin of obligatory¹

1425–75; late Middle English < Late Latin obligātōrius binding, equivalent to Latin obligā ( re ) to bind ( obligate ) + -tōrius -tory ¹

Example Sentences

After two years he left school for a year of obligatory military service in the Air Force.

From Los Angeles Times

Presumably the offer also includes the obligatory DoubleTree chocolate chip cookies upon check-in.

From Los Angeles Times

Recently, however, his obligatory ham and cheese toastie had been delivered to his room by a member of staff.

From BBC

Russian citizenship is now obligatory if you want to work or study or have an urgent medical help, Pavlo says.

From BBC

After the obligatory performance of “Louie Louie” at the end of the set, the players took their instruments off the stage and were gone.

From Los Angeles Times

Related Words

• compulsory 
• de rigueur 
• imperative 
• mandatory 
• requisite 
• unavoidable