means A person who resists or defies an established authority, government, or set of conventions.

from From the Latin 'rebellis' — built from 're-' (again) and 'bellum' (war). A rebellis was literally one who renews war: a defeated people who, having sworn peace, took up arms a second time. The word marched into English through Old French 'rebelle.' That same 'bellum' fuels 'belligerent' and 'antebellum' — war is the family business.