The Historical Thesaurus of English project was initiated by the late Professor Michael Samuels in 1965 and completed in 2008. It contains almost 800,000 word meanings from Old English onwards, arranged in detailed hierarchies within broad conceptual categories such as Thought or Music. It is based on the second edition of the Oxford English Dictionary and its Supplements, with additional materials from A Thesaurus of Old English, and was published in print as the Historical Thesaurus of the OED by Oxford University Press on 22 October 2009.
This electronic version enables users to pinpoint the range of meanings of a word throughout its history, their synonyms, and their relationship to words of more general or more specific meaning. In addition to providing hitherto unavailable information for linguistic and textual scholars, the Historical Thesaurus online is a rich resource for students of social and cultural history, showing how concepts developed through the words that refer to them. Links to Oxford English Dictionary headwords are provided for subscribers to the online OED, which also links the two projects on its own site.