From the Oxford English Dictionary:
The Historical Thesaurus of the OED (HTOED) is a semantic network of OED senses arranged by concept or meaning. It allows users to explore the different ways that meanings have been expressed in English over time, and to discover which synonyms were available for particular words in different periods. Its data has also been used to support various other research projects, such as the semantic tagging of historical corpora and the analysis of metaphorical patterns in English.
HTOED was created at the University of Glasgow from the late 1960s, and was largely based on data from the second edition of the OED. But as the OED continues to be revised and new words, senses, and phrases are added, these need to be linked to HTOED in order to present a complete semantic history of the language, and to enable HTOED to fully realize its potential to support a wide range of linguistic and historical research Over the past few years as part of the OED100 project we have been working to expand HTOED in this way, using a partially automated process: we developed a tool to automatically identify possible classifications of senses (based on features such as definition wording, cross-references, and labels), and a team of editors manually check and modify the suggested classifications. Through this project we have linked more than 55,000 further OED senses to HTOED categories so far.
Direct to Historical Thesaurus of the OED (HTOED)
Direct to HTOED How To Guide