if you can't remember the "right" word, you are suffering from lethologica (the inability to remember names is lethonomia). the more medical terminology for difficulty in finding the right words or remembering names is anomia.

here is an interesting British slang word for a "what's it's name": oojah
a Freudian slip is known as a parapraxis
and "speaking in tongues" is more properly called glossolalia

{gotta get more stuff into my postaday}

by the way, Lethe, in Greek mythology, was the river of forgetfulness in Hades; the dead drank from Lethe upon their arrival in the underworld.