A charterhouse (; ; ; ; ) is a monastery of Carthusian monks. The English word is derived by phono-semantic matching from the French word chartreuse and it is therefore sometimes misunderstood to indicate that the houses were created by charter, a grant of legal rights by a high authority.
The actual namesake is instead the first monastery of the order, the Grande Chartreuse, which St Bruno of Cologne established in a valley of the Chartreuse Mountains in 1084.
The London Charterhouse was the first English site to which this English version of the word was applied.