• synonyms


[uh-blig-uh-tawr-ee, -tohr-ee, ob-li-guh-]
  1. required as a matter of obligation; mandatory: A reply is desirable but not obligatory.
  2. incumbent or compulsory (usually followed by on or upon): duties obligatory on all.
  3. imposing moral or legal obligation; binding: an obligatory promise.
  4. creating or recording an obligation, as a document.
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Origin of obligatory

1425–75; late Middle English < Late Latin obligātōrius binding, equivalent to Latin obligā(re) to bind (see obligate) + -tōrius -tory1
Related formsob·lig·a·to·ri·ly [uh-blig-uh-tawr-uh-lee, ‐tohr‐, ob-li-guh‐, uh-blig-uh-tawr-uh-lee, ‐tohr‐, ob-li-guh‐] /əˈblɪg əˌtɔr ə li, ‐ˌtoʊr‐, ˈɒb lɪ gə‐, əˌblɪg əˈtɔr ə li, ‐ˈtoʊr‐, ˌɒb lɪ gə‐/, adverbob·lig·a·to·ri·ness, nounnon·ob·lig·a·to·ri·ly, adverbnon·ob·lig·a·to·ry, adjectiveun·o·blig·a·to·ry, adjective

Synonyms for obligatory

Antonyms for obligatory

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for obligatorily

Historical Examples of obligatorily

  • It is true that the chief of the clan never eats the totem ritually and obligatorily.

    The Elementary Forms of the Religious Life

    Emile Durkheim

British Dictionary definitions for obligatorily


  1. required to be done, obtained, possessed, etc
  2. of the nature of or constituting an obligation
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Derived Formsobligatorily, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for obligatorily



c.1400, from Old French obligatoire "creating an obligation, obligatory," and directly from Late Latin obligatorius "binding," from obligat-, past participle stem of obligare (see oblige).

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Online Etymology Dictionary, © 2010 Douglas Harper