A hidden memory mistaken for original creation, a thought, phrase, or melody resurfacing without recognition of its source, so that recollection masquerades as invention (psychological; technical). Cryptomnesia is usually unintentional, authorship blurred by forgetting.

Formed from Greek roots: krypto- “hidden” + mnēsis “remembrance.” The coinage is modern and diagnostic, naming a phenomenon as old as minds: memory working in disguise.