The word is: Lethologica
You may point to
http://www.chipublib.org/008subject/005genref/faqwordleth.html
of the Chicago Pub/ Lib to have a look.
(Lurker unlurking as this is up my tree; and back to lurking.)
"Raymond Arsenault, Ph.D." wrote:
> I have given up on this one. There is a word that describes the state of
> knowing a word and not being able to find it. We sometimes call this "tip
> of the tongue" or "mental block". I can't find the word, which is a nice
> little conundrum.
>
> Ray
>
> Raymond Arsenault, Ph.D.
