Word Study
de rigueur
OXFORD DICTIONARY
de rigueur, predic.adj. required by custom or etiquette (evening dress is de rigueur).
Etymology
F, = of strictness
THESAURUS
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, traditionalROGET THESAURUS
de rigueur
Compulsion
N compulsion, coercion, coaction, constraint, duress, enforcement, press, conscription, force, brute force, main force, physical force, the sword, ultima ratio, club law, lynch law, mob law, arguementum baculinum, le droit du plus fort, martial law, restraint, necessity, force majeure, Hobson's choice, compelling, coercive, coactive, inexorable, compulsory, compulsatory, obligatory, stringent, peremptory, forcible, not to be trifled with, irresistible, compelled, fain to, by force, by force of arms, on compulsion, perforce, vi et armis, under the lash, at the point of the sword, at the point of the bayonet, forcibly, by a strong arm, under protest, in spite of one's teeth, against one's will, nolens volens, by stress of circumstances, by stress of weather, under press of, de rigueur, with a gun to one's head, I'll make him an offer he can't refuse.For further exploring for "de rigueur" in Webster Dictionary Online