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"
a conflict of opposed ideas or attitudes or goals; "a collision of interests"
an accident resulting from violent impact of a moving object; "three passengers were killed in the collision"; "the collision of the two ships resulted in a serious oil spill"
(physics) an brief event in which two or more bodies come together; "the collision of the particles resulted in an exchange of energy and a change of direction"