The meaning of the name itself is quite simple: The whale was often sighted in the vicinity of the Island of Mocha, and "Dick" was merely a generic name like "Jack" or "Tom." The transformation of "Mocha" to "Moby" presented a greater mystery. Melville himself never explained the origin of the latter word. The answer will probably never be known. The whiteness of the whale has many different meanings. There are obvious ones that are innocence, purity, and cleanliness.
But there is also the aspect of white being something that people are repulsed by. Three of the main characters had their own thought of the representation of the whale. To Captain Ahab, Moby-Dick represents all the evil in the universe. To the first mate, Starbucks he is merely a whale to be killed for oil. To Ishmael, Moby-Dick represents nature in all its awe-inspiring beauty and terror.
The reason for Captain Ahab hatred towards the whale is because Captain Ahab who on a previous voyage lost his leg to the great white whale, Moby-Dick and he is now consumed with the desire to hunt him down and kill him. Moby-Dick is a Sperm Whale perhaps 90 to 100 feet long, has a snow-white wrinkled forehead, and a deformed lower jaw. He has a high pyramidical hump and a body streaked and spotted with the same whiteness of his forehead. Throughout the whole story the white whale is not only depicted as an unexplainable force of nature, but also given an almost divine quality, he is constantly compared to God, and as the people fear and revere God they also fear Moby-Dick and whales in general. From the beginning we are confronted with the image of the whale as the personification of power and strength, as S tubb says in the inn "If God where to be any fish he would be a whale." From this quote alone it is evident that the whale holds a great deal of power. Starbuck who is obviously a devoted christian is the only perso on the pequod that seems to think that Moby-Dick is nothing more than a whale, he says " This whale is a dumb brute who acts out of instinct." Starbucks fails to see the power that most of the other sailors believe the whale has.
Moby-Dick is cast in two roles by Melville. In one he a legendary, but real whale for the crew, the object of a wild and exciting chase through the seven seas. For Ahab, Moby-Dick is not only the living whale which removed from him his leg, but a symbol of evil and the scapegoat for Ahab's miserable existence. And to make this character even more obscure than Ahab's, Melville makes it clear that Moby-Dick is capable of the greatest violence. But we also see the Great White Whale swimming tranquilly at sea unmindful of man until attacked. This coincides with Melville's emphasis upon the whiteness of the whale for he suggests that whiteness has come to mean for man both tranquility and good, as well as terror and evil.
The meaning of Moby Dick is so involved and complex that few critics would agree upon a single accepted interpretation. The novel can be approached from many different viewpoints. Thus, it would be highly superficial to attempt to suggest one basic meaning and we therefore offer only one approach to the novel.