Difference between Controversial and Contentious

CONTROVERSIAL vs CONTENTIOUS: ADJECTIVE

Involving or likely to cause controversy
Inclined or showing an inclination to dispute or disagree, even to engage in law suits
Having or showing a ready disposition to fight
Given to contention; quarrelsome. : argumentative.
Fond of contention; given to angry debate; provoking dispute or contention; quarrelsome.
Relating to contention or strife; involving or characterized by contention.
Contested; litigated; litigious; having power to decide controversy.
Jurisdiction over matters in controversy between parties, in contradistinction to voluntary jurisdiction, or that exercised upon matters not opposed or controverted.
Marked by heated arguments or controversy.
Given to struggling with others out of jealousy or discord.
Involving or causing contention; controversial.

Of or pertaining to controversy; characterized by or connected with disputation; disputatious: as, a controversial discourse.

In law, relating to causes between contending parties.
Relating to or characterized by contention or strife; involving contention or debate.
Apt to contend; given to angry debate; quarrelsome; perverse; litigious.

Objectionable, Dubious, Provocative, Problematic, Thorny, Controversy, Divisive, Arguable, Moot, Polemic, Polemical, Disputable, Disputed, Debatable, Contentious

Controversy, Problematic, Dispute, Disputes, Thorny, Divisive, Disputative, Battleful, Aggressive, Bellicose, Argumentative, Litigious, Disputatious, Combative, Controversial

Objectionable, Dubious, Provocative, Problematic, Thorny, Controversy, Divisive, Arguable, Moot, Polemic, Polemical, Disputable, Disputed, Debatable, Contentious

Controversy, Problematic, Dispute, Disputes, Thorny, Divisive, Disputative, Battleful, Aggressive, Bellicose, Argumentative, Litigious, Disputatious, Combative, Controversial

Steve Bannon and controversial counterterrorism advisor Sebastian Gorka.
The action will have highly controversial environmental effects.
Does he still stand by his controversial suggestions?
Mulick, Controversial therapies for autism and intellectual disabilities.
What we call ourselves can also be controversial.
These two verses are arguably the most controversial ones in the Pentateuch and certainly the most controversial in Leviticus.
Because the natural right of property was controversial, so the administration of any substantive constraint along these lines was bound to be controversial.
Representative of differing viewpoints on controversial subjects Students have the right to information on both sides of a controversial issue.
Stevens was a controversial governor in his time, and has become more controversial in retrospect.
Academic research meets practice: Why controversial results are not controversial.

However, not every divorce and separation is contentious.
When is a contentious divorce declared in China?
Politics is too contentious: it might involve Republicans.
Abraham, was very contentious always willing to please.
The issue of model calibration can be contentious.
Distinction awards have been contentious since their introduction.
It remains a contentious and culturally significant issue.
Noise in the neighbourhood is a contentious issue.
If the elders are contentious, the church will be contentious.
Contentious Issues Panels decide the departmental strategy for handling major contentious issues.