Thesauruses are systemized collections of synonyms and antonyms that are available in both print and digital formats. Examples of popular online English thesauruses include Synonym.com, Roger's Thesaurus online at Thesaurus.com, The Collins English Thesaurus and the MacMillan English Thesaurus.
Many online dictionaries include thesauruses at their homepages, each with varying features. The Collins English Thesaurus, as an example, includes a list of synonyms in foreign languages in addition to English synonyms, as well as distinct searches by either American English and global English. The Merriam-Webster online thesaurus includes related words and near-antonyms along with more direct synonym and antonym entries.