Some words do live only in the dictionary and not in the mind (of any native speaker).
These are misreadings, in papyri and inscriptions especially, variants in manuscripts, and conjectures long rejected, but preserved in dictionaries compiled when older editions were current. The following is W. W. Skeat's description of such words from The Transactions of the Philological Society (1885-7) II. 350-1
"Report upon ‘Ghost-words’, or Words which have no real Existence... We should jealously guard against all chances of giving any undeserved record of words which had never any real existence, being mere coinages due to the blunders of printers or scribes, or to the perfervid imaginations of ignorant or blundering editors."
For a readily accessible list of such specimens, see the corrigenda at the end of the Revised Supplement to LSJ (as in the integrated edition, not the separate 1996 vol.).