"The Whipping": the title obviously describes what happens in the poem—a boy is savagely whipped and chased and cornered and beaten by some large, crazy woman. Keep in mind that we never learn what exactly the relationship between these two is, which makes things just a little strange. There's something about that word "the" that makes this poem seem scary, ominous, dangerous. Think of it like this: the Flood, the Deluge, the Apocalypse… the Whipping. It's not just scary and dangerous, but something that recalls the horrors of slavery in the American south. You can read more about that terrible time in history right here.
The other thing about a title like "The Whipping" is that we can't help thinking it describes something that has happened over and over and over, kind of like the sunrise, the sunset, the feeding, and so on. In short, with a title like "The Whipping," we think two things: this is something scary that definitely involves violence and punishment, and it's a violent encounter that has happened a whole lot of times. Well, that sounds like a charming subject for a poem now, doesn't it?