Nominal Aphasia, Dysnomia, Anomia, Neologisms

I started reading Wikipedia and one thing led to another. When I call my Twitter tweets 'chirps' and 'twirps,' I do that on purpose because I think it's funny, but I know perfectly well that they're actually called tweets. But other times, I really can't recall people's names, and I can't recall nouns. I have to say 'that thing' and then make gestures with my hands.