What is the Historical Thesaurus of the OED

By Christian Kay, professor emeritus, University of Glasgow, and editor of the Historical Thesaurus
Please note: the links in this article require subscriber access to the OED online. An interactive guide to the Historical Thesaurus is also available on open access.

The Historical Thesaurus of the OED is a unique resource for scholars and lovers of the English language. Rather than organize words alphabetically, as in a dictionary, it organizes them according to their meanings. It also organizes them chronologically, going back to the roots of English in the Anglo-Saxon period, over thirteen hundred years ago. It is thus possible to see how the expression of a concept has developed, whether it be a long-established one, such as sovereignty, or a more modern one, like radio.

Compiling the Historical Thesaurus

The Thesaurus was compiled over a period of 44 years in the English language department at the University of Glasgow. It was the brainchild of Professor Michael Samuels, who saw a gap in the materials available for studying the history of the English language. While the OED is a hugely rich resource for studying the histories of individual words, there was no parallel resource for studying the history of concepts as they are expressed in words. In 1965 Samuels announced, in a talk to the Philological Society, that his department would undertake the task of producing such a resource; in 2009 the work was published in print as the Historical Thesaurus of the OED.

The first step in this mammoth undertaking was to extract the necessary information from the OED: the meaning, its dates of use, part of speech, and definition. Since computers were barely on the horizon in humanities research, this task was done in the traditional way, by reading the dictionary and transcribing the information onto paper slips. Over the years, as Oxford University Press published supplements and then a second edition of the OED, new information was added or matched to the old. This process is being continued by OUP staff as the OED‘s third edition progresses, thus keeping the Thesaurus up-to-date.

Carnation to pink

Samuels’ contention was that studies of the development of the English vocabulary would be assisted if words could be viewed in the context of other words of similar or related meanings. Thus a student of Shakespeare might notice that the author does not use the colour adjective pink. Looking up pink in the OED shows that it is not recorded in English until after Shakespeare’s death, and was therefore not available to him. This information might lead the researcher to wonder whether Shakespeare or earlier writers had other words for the concept at their disposal. Looking up pink in the Thesaurus, where the complete range of words meaning pink is displayed, reveals several possibilities. One such is carnation, first recorded in 1565/78; other words were also available at the time. The OED reveals that Shakespeare used carnation some 30 years later in Love’s Labours Lost. The example demonstrates what a powerful tool the OED and Thesaurus make in combination.

Anyone who wants to explore further how pink developed, or how it relates to other colour terms, can return to the Historical Thesaurus and examine the hierarchy in the left-hand panel. Scrolling upwards shows how pink relates to the general concept of colour, while scrolling downwards leads to specific shades of pink, and then to related categories, such as dyestuffs. This example illustrates the classificatory principle on which the Thesaurus is based: a progression from the most general terms to the most specific.

Classifications in the Historical Thesaurus

Establishing the classification was the second major undertaking for the project. At its very highest level, the Historical Thesaurus has three broad divisions: The external world, The mind, and Society, reflecting the main areas of human activity, as represented in the language of English speakers. Scrolling through The external world, we find eight categories at the next level, including The earth, The living world, and Sensation. The living world in turn contains categories at the next level for Animals, Plants, and People, and so on down the hierarchy. It is thus possible to work down through the various levels to reach the names of a particular type of plant or animal, or to go back up the hierarchy to reach the External world again. Similar principles apply to The mind, which contains sections such as Mental capacity, Emotion, and Language, and to Society, which covers activities as diverse as Warfare, Education, and Occupation.

Social change through language

In addition to providing answers to linguistic questions, the Thesaurus is a rich source of cultural information. The words we use reflect not only how we live, but how we think about the world, and the same is true about the vocabulary of previous generations. A scroll through a section such as Food or Inhabiting/dwelling illustrates how far people’s lives have changed over time. Social and cultural factors may also help to explain why new words enter a language and others drop out of use. The twentieth century, for example, saw the development of a whole new vocabulary for computing, while many traditional farming terms disappeared as technology developed. It also saw the recognition of new categories of people, such as teenagers or wrinklies, reflecting an increased focus on age as a social factor. Similar effects can follow political events, such as the Norman Conquest; many new words in categories such as Law or Religion are first recorded in the decades after 1066, indicating comprehensive changes of practice in these areas.

It is also interesting to look at the sources of words. There are, for instance, large numbers of expressions in English to describe people whom the speaker holds in contempt, such as whelp or muckworm. The OED gives etymological information for each of these words, but a glance at the Thesaurus category contemptible person sets off other trains of thought. Many words show contempt by equating human beings with animals, many belong to the slang register, and many are first found in the sixteenth century, a period of great inventiveness in the English language. Many, especially of the latter, have come and gone fairly quickly, as slang words tend to do—partly because they lose their impact, and partly because they may be considered unduly offensive in more sensitive times.

Where next with the OED Online?

  1. In addition to this article, Christian Kay has written about How to use the Historical Thesaurus, while Marc Alexander and Kate Wild offer a case study on ‘Men’, ‘women’, and ‘children’ in the Thesaurus.
  2. With subscriber access to the OED Online, you can browse the Thesaurus by subject classifications or click through from an OED entry or sense to find synonyms over time. For example, how has the language of marriage changed over the past 1000 years? Or the language of weak intellect, from idiot (c.1480) to divvy (1987) via moonling (1631).

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