Synonyms for Forgotten (same or very similar meaning)
WordNet sense 1 (no longer known; irretrievable):
lost
WordNet sense 2 (incapable of being recovered or regained):
irrecoverable, unrecoverable
WordNet sense 3 (not noticed inadvertently):
disregarded
WordNet sense 4 (not noticed):
unnoticed
From the ODE community, based on WordNet
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