Anomia is a brain disorder that makes it hard to remember the names of people and objects. Anomia can sometimes be a symptom of a tumor or stroke.
Anomia is a very specific kind of memory loss, which makes suffers remember people but forget their names, or know what something is but be unable to come up with what it's called. It's usually caused by some brain trauma, like an accident or cancer. Although there is a word spelled the same way in Greek, anomia is formed from two Latin roots, a-, "without," and nomen, "name."