Is there a term for when a character is named after a trait they possess?

Is there a term for when a character is named after a trait they possess? Some examples are Hiro (from Heroes or Snow Crash); a person who is constantly talking named Gabby; or a teacher named Mr. Pencil.

Aptronym: a name that is aptly suited to its owner.

Some examples from the Wikipedia entry:

• Jules Angst, German professor of psychiatry, has published works about anxiety
• Jack Armstrong, retired MLB (Major League Baseball) pitcher
• Jeff Bagwell, Retired MLB 1st Baseman
• Grant Balfour, MLB Middle Reliever, although as a pitcher ball four is generally not a good thing
• Alan Ball, a name shared by two English footballers (father and son), the latter of whom played in the 1966 World Cup winning team
• Lloy Ball, American volleyball player
• Michael Ball, footballer
• Colin Bass, British bassist in the rock band Camel
• Eric Bass, American bassist in the rock band Shinedown
• Layne Beachley, Australian world champion surfer
• Chip Beck, professional golfer
• Sara Blizzard, meteorologist (television weather presenter) for the BBC
• Lorena Bobbitt, arrested for 'bobbing' a certain part of her husband's anatomy
• Usain Bolt, Jamaican sprinter, Olympic Gold medalist, 100m and 200m world record holder
• Peter Bowler, cricketer (in fact, primarily a batsman)
• Russell Brain, neurologist

Edit: it appears that "aptronym" applies to real persons, whereas the OP may be asking about fictional characters. I do not know whether "aptronym" can be correctly applied to fiction.

Edit 2: I see that @Jonathan submitted charactonym, which is specifically for fictional characters. However, it does appear that aptronym can apply to fictional as well as real characters... so perhaps two separate words are not necessary?

I suppose one could call the character names allegorical. From the The Free Dictionary:

al·le·go·ry (l-gôr, -gr) a. The representation of abstract ideas or principles by characters, figures, or events in narrative, dramatic, or pictorial form. b. A story, picture, or play employing such representation. John Bunyan's Pilgrim's Progress and Herman Melville's Moby Dick are allegories.

Examples in Pilgrim's Progress are characters like Obstinate, Faithful, and of course, Christian.