namesia
Inability or slowness to recall peoples' names. Especially in the case of names that you should be able to remember because you see the person more than occasionally. A variation of namesia is always wanting to call someone by a different name because they remind you of someone else (see "clonesia").
At the family reunion, I was embarrassed that my namesia prevented me from recalling my cousin's name.
namesia
Amnesia related to forgetting people's names
Jack has namesia.He could not remember his wife's name