Question:
Has anyone heard of a memory deficit that is characterized by aninability to remember what things are called (aka chronic failure toencode/retrieve lexical tags)? You know when you can't remembersomeone's name despite the fact you know who he or she is? Well whatI'm talking about is like that but it happens for many more thingsthan just people (e.g., names of objects and places places, the titleof a movie you just watched, the names of characters in books orfrequently watched tv shows). Does this chronic thing have a name?

Answer: I think you mean aphasia.

But aphasia is too broad a category. Aphasia (or dysphasia, for milderforms) can involve various aspects of expressive and/or receptivelanguage impairment. Blair describes a rather circumscribed aspect ofexpressive aphasia/dysphasia--assuming, of course that the difficultyis indeed behyond the normal range, which remains to be seen; v. myoriginal response. (Consider other possibilities: adequate naming butimpaired syntax, for example...)

It's called "dysnomia", which means some impairment of naming; cf."anomia" which means completely impaired ability to name things.