[1] : The Collaborative International Dictionary of English v.0.48

de rigueur \de ri`gueur"\ f. see 2d rigor.
   according to strictness of etiquette, rule, or the like;
   obligatory; strictly required.
   webster 1913 suppl.
see also:
rigor 

[2] : WordNet (r) 2.0

de rigueur
     adj : required by etiquette or usage or fashion; "instruction as
           to when and where a silk hat is de rigueur"

[3] : Moby Thesaurus II by Grady Ward, 1.0

34 moby thesaurus words for "de rigueur":
   accepted, acknowledged, admitted, approved, au fait, becoming,
   being done, binding, comme il faut, conformable, conventional,
   correct, customary, decent, decorous, done, formal, imperative,
   imperious, mandatory, meet, must, necessary, nice, obligatory,
   orthodox, peremptory, proper, received, recognized, required,
   right, seemly, traditional

De Rigueur >> D Words
De Rigueur, definition of term: De Rigueur
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