Silicon Valley Dictionary - Urban dictionary meets Silicon Valley
Writefull Thesaurus - A Google Docs add-on that uses AI to give you synonyms
Meaning Monkey - Find the definition and meaning of anything.
Dictionary Anywhere - Dictionary Anywhere is an open-source and easy-to-use browser extension for Mozilla Firefox and Google Chrome that allows you to check definitions easily while browsing the web.
Words For That - the reverse-Urban Dictionary of the internet
FoxType Thesaurus - Visualize similar words for _____