Specialised dictionaries are defined here by the specialised nature of the subjects they treat, focusing on particular subject fields, professional practices or even leisure activities such as sports 1 with the aim of helping the user to acquire specialised knowledge, read specialised texts or engage in specialised translation. They can usefully be thought of as LSP (language for special purposes) dictionaries or special-purpose dictionaries (Nielsen 1994:1), although the definition of LSP can be questioned as being too broad (Sager, Dungworth, McDonald 1980: 3) or subject to national variations (Humbley 2007). Dictionaries dealing with specific language issues (pronunciation, proverbs, etc.) are not dealt with here, and no advice is offered on writing a specialised dictionary. The survey is confined to Western European languages. It is not possible, furthermore, to find any clear cut-off between dictionaries and encyclopaedias, although prototypically dictionaries aim at the language of specialised fields, whereas encyclopaedias focus on the extra-linguistic. Fuertes-Olivera and Tarp (2014:7) define the category as “dictionaries, encyclopaedias, lexica, glossaries, vocabularies and other information tools outside general cultural knowledge”. Indeed, as Dancette and Réthoré (1997: 230) claim, linguistic and encyclopaedic methods complement one another in the making of the specialised dictionary. Term bases are subsumed in this chapter: they were derived from the automation of cardboard term records kept by specialised translators, thus bypassing the printed book stage, unlike general language lexicography.