This ' ghost word ' as it was called, was defined as a chemical term.

In any case, the Massoretic 'Eqrdn is nothing but a ghost word . The non-biblical attestations all confirm that the original was *'Aqqaron as evidenced by the Akkadian (especially (URL) Am-qar-ru-na and (URU) Am-qar-ru-u-na= Amqaruna = *'Amqarona < *'Aqqarona) and Greek (Akk[TEXT NOT REPRODUCIBLE IN ASCII] = Akkaron) transcriptions.

Indeed, the Invisible Man ultimately coins his own, hybrid vocabulary, comprised of what I call "ghost-words." A Merriam-Webster on-line dictionary defines ghost word as "a word form never in established usage." The OED traces the term's origin to an 1886 journal report that proclaims them words with "no real existence." This same report declares, "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." Ghostwords are marginalized words, words that appear in no dictionary of "established," or white, usage.

It is probably a ghost word and should therefore be omitted from dictionaries of medieval Latin.