• Longman Dictionary of Contemporary English: Use this website to learn about a word. You can listen to the word, learn the definition, and learn the part of speech.

Longman Dictionary of Contemporary English | LDOCE

• Macmillan: great dictionary and thesaurus

Macmillan Dictionary | Free English Dictionary and Thesaurus

• Merriam-Webster: audio for the words

Dictionary by Merriam-Webster: America's most-trusted online dictionary

• Merriam-Webster: pronunciation dictionary

Perfect pronunciations exercises | Learner's Dictionary (learnersdictionary.com)

• Dictionary.com: English-English

Dictionary.com | Meanings and Definitions of Words at Dictionary.com

• Thesaurus.com: online thesaurus

Synonyms and Antonyms of Words | Thesaurus.com

• The Free Dictionary: comprehensive

Dictionary, Encyclopedia and Thesaurus - The Free Dictionary

• Wikipedia: free encyclopedia

Wikipedia

• Wordnik: Founded by former editor-in-chief of the Oxford American Dictionary, this site provides actual examples of words taken from “real-time” sources such as blogs and websites. It aims to help learners understand and use words naturally from the variety of contexts in which words occur.

Wordnik

• Collins Advanced Dictionary of American English

Collins English Dictionary | Definitions, Translations, Example Sentences and Pronunciations (collinsdictionary.com)

• Collins American Thesaurus

Collins Thesaurus | Synonyms, Antonyms and Definitions

• The American Heritage Dictionary of English

American Heritage Dictionary - Search