From Longman Dictionary of Contemporary Englishconfederatecon‧fed‧e‧rate /kənˈfedərət/ noun [countable] 1 formalHELP someone who helps someone else do something, especially something secret or illegal SYN accomplice The young woman was his confederate, of course.2 PPGa member of a confederacy —confederate adjective
Examples from the Corpus
confederate• Men are more likely to be assessed on active behaviours like administration of electric shocks to an experimental confederate.• Billy Sullivan felt worried as he waited by the Rotherhithe Tunnel entrance for his confederates.• A riot began when drug traffickers tried to free their jailed confederates.• The two of us, for once, were confederates.Origin confederate (1300-1400) Late Latin past participle of confoederare, from Latin com- ( → COM-) + foedus ( → FEDERAL) 