Synonyms for Constituent (same or very similar meaning)
WordNet sense 1 ((grammar) a word or phrase or clause forming part of a larger grammatical construction):
grammatical constituent
WordNet sense 2 (an abstract part of something):
component, element, factor, ingredient
WordNet sense 3 (constitutional in the structure of something (especially your physical makeup)):
constitutional, organic, constitutive
WordNet sense 4 (basic and fundamental):
essential
From the ODE community, based on WordNet
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