[ prɪ'rɒgətɪv ]
■ noun
1》 a right or privilege exclusive to a particular individual or class.
2》 (in UK law) the right of the sovereign, theoretically unrestricted but usually delegated to government or the judiciary.
■ adjective arising from or relating to the royal ~.
Origin
ME: via OFr. from L. praerogativa '(the verdict of) the political division which was chosen to vote first in the assembly', feminine of praerogativus 'asked first', from prae 'before' + rogare 'ask'.