Source : Webster's Revised Unabridged Dictionary (1913)

Controversial \Con`tro*ver"sial\, a. [Cf. LL. controversialis.]
   Relating to, or consisting of, controversy; disputatious;
   polemical; as, controversial divinity.

Source : WordNet®

controversial
     adj : marked by or capable of arousing controversy; "the issue of
           the death penalty is highly controversial"; "Rushdie's
           controversial book"; "a controversial decision on
           affirmative action" [ant: {uncontroversial}]