(1) n. Created in the late 1930s, by Bob Kane, Batman's main goal was to be a "superhero who would sell as well as Superman
Like Superman, he was given a tragic past and a reason to fight. But, unlike Superman, he has no powers of his own, and relies on theatrics and fear to get his message across. He dresses like a Bat to invoke fear in his enemies.
He has a network of associates known as the "Bat Family," which includes: Nightwing
(Dick Grayson, the first Robin), Robin
(Tim Drake), Oracle (Barbra Gordon, the first Batgirl), Batgirl
(Cassandra Cain). Previously, he has taken Jason Todd and Stephine Brown under his wing, both as Robins (the second and fourth ones, respectively), and both were murdered.
Since his inception, Batman has appeared in comic books, cartoons, movies, plays, and various other media. He currently stars, and is featured, in various DC comic books.
also see: The Batman, The Dark Knight, Bruce Wayne, vengence, the night
(2) v. To suddenly appear or disappear without bringing attention to oneself, as Batman is known for doing.