Hmmm....
How interesting.
We were discussing this just the other day...
Not at a level where its actually a disability, but... K2 used what I considered an "inappropriate term" for this event (word recall failure... getting "no word" or "wrong word" back on brain search...), so we talked about what this really is, when people struggle with it on a daily basis: dysnomia. Its a learning disability, like dyscalcula, dyslexia, dysgraphia, etc....
It is either frustrating, or hilarious - or both.
If the person with the disability has a sense of humour, it really helps!