from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Required by the current fashion or custom; socially obligatory.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Necessary according to etiquette, protocol or fashion.
from the GNU version of the Collaborative International Dictionary of English
- According to strictness (of etiquette, rule, or the like); obligatory; strictly required.
from The Century Dictionary and Cyclopedia
- n. Strictly required, as by etiquette, usage, rule, etc.; essential; imperative: as, full dress is de rigueur.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. required by etiquette or usage or fashion
French : de, of + rigueur, rigor, strictness.(American Heritage® Dictionary of the English Language, Fourth Edition)
French de rigueur ("required"), from de ("of") + rigueur ("rigour/rigor"). (Wiktionary)