a. One who advocates the abolition of social inequities. b. Leveller A member of an English radical political movement arising in the Parliamentarian forces of the 1640s and advocating universal male suffrage, equality before the law, parliamentary democracy, and religious tolerance.

Heres the link to a pamplet printed by the  Levellers in 1649 in defense of mutineers (those who refuse to obey authority)  in Burford, England. —- http://www.bilderberg.org/land/case.htm