from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Exceptionally exact or vivid memory, especially as associated with certain mental illnesses.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An elevated level of memory recall.
from The Century Dictionary and Cyclopedia
- n. Unusual power of recollection.
hyper- + (a)mnesia.(American Heritage® Dictionary of the English Language, Fourth Edition)
From hyper- and the root mnesia relating to memory. (Wiktionary)