See discussion under Grundgesetz addressing the distinction between the German Basic Law and the US Constitution. The German basic or fundamental rights are established in a so-called "Grundgesetz" (Basic Law), which due to a number of factors is more of a hybrid between a constitution and a more malleable legislative code.
There are multiple definitions - click on the translation that matches your context.
something that the constitution says that you are legally allowed to do or have
Police violated a burglary suspect's constitutional right to privacy when they located him using cellphone tracking information without first obtaining a warrant.