Silicon Valley Dictionary - Urban dictionary meets Silicon Valley
Glosbe - Huge collaborative massively multilingual dictionary.
Writefull Thesaurus - A Google Docs add-on that uses AI to give you synonyms
Visuwords - The fun and free way to look up definitions. THE graphical dictionary and visual thesaurus.
FoxType Thesaurus - Visualize similar words for _____
DocTranslator - Instantly translate and keep the formatting of any document in any language. Free!