Synonyms for Throwback (same or very similar meaning)
WordNet sense 1 (an organism that has the characteristics of a more primitive type of that organism):
atavist
WordNet sense 2 (a reappearance of an earlier characteristic):
atavism, reversion
WordNet sense 3 (characteristic of an atavist):
atavistic
WordNet sense 4 (opposing progress; returning to a former less advanced state):
regressive
From the ODE community, based on WordNet
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