Old English – The English spoken in the period before 1100AD. This differs a great deal from later forms of the language, since the introduction of French vocabulary following the Norman Conquest of 1066 meant that many Old English words had been replaced by about 1150AD.

Metaphor – The conceptualisation, or understanding, of one domain of meaning in terms of a different domain. This is a matter of thought, but we can see evidence of it through vocabulary from one area (e.g. journeys) being used in another area (e.g. life).

Strong link – This is where we have a cluster of word senses which we believe give enough evidence to demonstrate a systematic metaphorical link between two categories.

Weak link – This is where we have found only a small amount of evidence for a metaphorical link between categories. The lexical evidence might be found only in poetry or in a few isolated senses, but does not constitute a systematic link.

Date of metaphor inception – The 50-year block of time in which we have the very first evidence of metaphorical connection between two categories.

Start era – See ‘Date of metaphor inception’.

Examples of metaphor – These are words which have been selected as showing evidence of the metaphorical link between two categories. They do not represent all potential evidence of a metaphorical link between the categories and there may well be further word senses which add to this picture.

Category – A section of the Historical Thesaurus which contains the vocabulary of a specific area of meaning in English. These are typically centred around easily graspable concepts, such as Birds, Imagination, and Social position.

Direction – The direction of transfer between categories, e.g. dazzling in relation to beauty shows a transfer of vocabulary from Light to Physical appearance, rather than the other way round. The direction of transfer is based on the evidence in the Historical Thesaurus and the Oxford English Dictionary, taking into account attestation dates of specific word senses.