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


required as a matter of obligation; mandatory: A reply is desirable but not obligatory.
incumbent or compulsory (usually followed by on or upon): duties obligatory on all.
imposing moral or legal obligation; binding: an obligatory promise.
creating or recording an obligation, as a document.

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. 2019

British Dictionary definitions for unobligatory



required to be done, obtained, possessed, etc
of the nature of or constituting an obligation
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 unobligatory



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).

Online Etymology Dictionary, © 2010 Douglas Harper