General Dictionaries:
* Merriam-Webster: [https://www.merriam-webster.com/](https://www.merriam-webster.com/)
* Oxford English Dictionary: [https://www.oed.com/](https://www.oed.com/)
* Dictionary.com: [https://www.dictionary.com/](https://www.dictionary.com/)
* Cambridge Dictionary: [https://dictionary.cambridge.org/](https://dictionary.cambridge.org/)
* Vocabulary.com: [https://www.vocabulary.com/](https://www.vocabulary.com/) (This one is great for learning new words and exploring definitions in context.)
Specialized Dictionaries:
* Medical Dictionaries: [https://www.merriam-webster.com/medical](https://www.merriam-webster.com/medical)
* Legal Dictionaries: [https://www.law.cornell.edu/wex/](https://www.law.cornell.edu/wex/)
* Slang Dictionaries: [https://www.urbandictionary.com/](https://www.urbandictionary.com/)
Tips for Choosing:
* Consider your needs: What kind of word are you looking up? Do you need a formal definition or a more informal one? Are you interested in etymology or pronunciation?
* Compare different sources: Sometimes, different dictionaries will provide slightly different definitions or emphasize different aspects of a word's meaning.
I hope this helps! Let me know if you have any other questions.