This chapter focuses on ways to expand the conlang lexicon further by considering aspects of semantics (word and sentence meaning) such as denotation, connotation, polysemy, metaphor and the development of word networks (semantic fields). It also discusses words whose meaning depends on personal, social, spatial, temporal and textual contexts (pragmatics). This chapter also provides conlanging practice, offers a step-by-step guide to expand your lexicon taking into consideration various semantic and pragmatic aspects, and illustrates semantic and pragmatic aspects of the Salt language.

Historical thesauri are indispensable tools for understanding the historical lexicon of English. The arrangement of historical lexis by semantic field reveals patterns in vocabulary which cannot be seen in an alphabetical ordering, and so historical thesauri are essential for the investigation of cultural development and the history of ideas as well as charting the evolution of the lexicon. This chapter gives examples from the Historical Thesaurus of English and its related projects, including A Thesaurus of Old English, The Bilingual Thesaurus of Everyday Life in Medieval England and Love, Sex, and Marriage: A Historical Thesaurus. It enumerates the key principles of a historical thesaurus, discusses sources of lexical data as well as the organisational principles by which historical thesauri arrange words, and overviews research projects in the history of English which have been made possible by historical thesauri.