Heathcliff: The English heath moors were considered a wild, haunted, unforgivable and untamable landscape, and that fits very well with Heathcliff's character.
Lockwood: one of the two narrators of the book, he is a different take on the story. He has a very skewed persepective, and "several critics have remarked on his name as hinting at a 'locked or closed mind.'" His sometimes rigid misconceptions could be symbolized in his name.
Earnshaw: The name itself could refer to the family's tendency to prefer wealth and status over other things. Catherine marrires the more "established" Linton, and Hindley is only kind to Heathcliff in the end to try to get money from him. They emphasize "earning" over other things. The Lintons however, had wealth, and didn't need such an obvious name to indicate it. It just needed to be a refined, fine-sounding name to represent their wealth and stature.
Heathcliff is really the only character that does not have a last name in the book. It almost serves as a constant reminder of how he is a outsider with no status and there is little that can be done about because he was brought into the Earnshaws family that way.
Just like Heathcliff Lockwood is an outsider to the story however he poses as more of a fly on the wall rather than someone who partakes in the story.
However the constant use of names repeating like Catherine Earnshaw to her daughter Catherine Linton and Edgar Linton to his nephew Linton serves to show the never ending cycle of disappointment and broken heart. Just like Catherine her daughter ends up in an unhappy marriage and just like his uncle Linton ends up being submissive and weak. Almost like history has no choice but to repeat its self.
WHAT CHAPTER IS THIS IN