Definitions of confederate:

noun: someone who assists in a plot
noun: a supporter of the Confederate States of America
noun: a person who joins with another in carrying out some plan (especially an unethical or illegal plan)
verb: form a confederation with; of nations
verb: form a group or unite
adjective: of or having to do with the southern Confederacy during the Civil War
Example: "Confederate soldiers"
adjective: united in a confederacy or league