Synonyms for Conventional (same or very similar meaning)
WordNet sense 1 (represented in simplified or symbolic form):
schematic
WordNet sense 2 (of or relating to a style of art in which objects do not resemble those known in physical nature):
nonrepresentational
WordNet sense 3 (conforming with accepted standards):
established
WordNet sense 4 (adhering to what is commonly accepted):
orthodox
WordNet sense 5 (rigidly formal or bound by convention):
ceremonious
WordNet sense 6 (being in accord with established forms and conventions and requirements (as e.g. of formal dress)):
formal
WordNet sense 7 (lacking spontaneity or originality or individuality):
stereotypical
WordNet sense 8 (rigidly conventional or old-fashioned):
square, straight
WordNet sense 9 (unimaginatively conventional):
conservative
WordNet sense 10 (in accordance with convention or custom):
customary
WordNet sense 11 (widely accepted as true or worthy):
accepted
WordNet sense 12 (consisting of or derived from tradition):
traditional
From the ODE community, based on WordNet
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