Sometimes, there is a difference between American English and British English.
Fortunately, Macmillan Dictionary gives comprehensive information about both British English and American English. If you select British English as your default setting, you will see entries which use British spelling and show British pronunciation. Similarly, if you choose American English as your default setting, you will see entries which use American spelling and show American pronunciation.
You can switch from British English to American English and vice versa using the link at the very end of each entry. Some definitions may also contain a brief comment about the difference between American English and British English uses of the word.
Read more about British and American Pronunciation