Cambridge Dictionaries (Clear, simple and accurate definitions using easy-to-understand language)

Collins Dictionary (Dictionaries in English, French, German, Spanish, Italian. Translator, Thesaurus, Words & Language, Word Games).

Oxford Dictionary (Oxford publishes many different types of dictionaries, from bilingual dictionaries, dictionaries for English learners, and children’s dictionaries, to dictionaries for research and study. Perhaps the most well known is the Oxford English Dictionary (OED), the definitive historical record of the English language.