The Oxford Thesaurus An A-Z Dictionary of Synonyms - controversialadj.

1) debatable, disputable, questionable, moot, doubtful, unsettled: Who will run the department is a controversial matter. 2) polemical, dialectic, litigious, factious: She has studied the controversial writings of the 19th-century feminists. 3) disputatious, argumentative, contentious; provocative: Race relations have remained a controversial issue for centuries.