partisan
A. -adjective
(=one-sided) parcial
(=of party) partidista (military) guerrillero
B. -noun partidario (m) / partidaria (f) (of de) (military)   partisano (m) / partisana (f), guerrillero (m) / guerrillera (f)
C. -compound
·partisan warfare -noun guerra (f) partisana