1881, from French égalitaire, from Old French egalite "equality," from Latin aequalitatem (see equality). Originally often in egalitarian despotism, such as the government resulting from the French Revolution or the ideas of the communists. The noun, "person who favors egalitarianism," is from 1920.
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.
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Definitions of egalitarianism
the doctrine of the equality of mankind and the desirability of political and economic and social equality;