There have been several important formal changes to the United Kingdom’s constitution over the past few decades, including devolution to Northern Ireland, Scotland, and Wales; the incorporation of the European Convention on Human Rights in domestic law; and the creation of a new Supreme Court. This article is about the informal semantic changes that may have accompanied these formal changes. It focuses on several central concepts: parliamentary sovereignty, the rule of law, the separation of powers, devolution, and human rights. Using a recently developed machine learning method to analyse a massive corpus of parliamentary debate, the article gauges the extent to which these concepts have become more (or less) related to the meaning of the ...