Google's English dictionary switched from the Collins COBUILD Advanced Learner's English Dictionary to the Oxford Pocket Dictionary of Current English. The definitions from the Collins dictionary are easier to understand, while the Oxford dictionary is more traditional.
Here are two definitions of the word "swot":
Collins: "If you call someone a swot, you disapprove of the fact that they study extremely hard and are not interested in other things."
Oxford: "A person who studies hard, esp. one regarded as spending too much time studying."