The phrase "a known opponent" is correct and usable in written English.
It can be used when referring to someone who is recognized or identified as an adversary in a particular context, such as sports, politics, or competition.
Example: "In the upcoming debate, she will face a known opponent who has a strong track record in public speaking."
Alternatives: "a recognized adversary" or "an established rival."
Deliberately bring up a known opponent of the person's views, and see what is the thinking about them.
Mr Rajan is a known opponent of this and insisted the process would be "transparent".
The imam of the mosque that was bombed was a known opponent of the Houthi movement and a part-time army commander, the officials said.
Col Von Stauffenberg, along with von Kleist's father - a known opponent of Hitler - and others involved in the plot were arrested and later executed.
In the first few years of the 14th century Thomas witnessed three charters of Coupar Angus Abbey in the company of Robert Wishart, Bishop of Glasgow, a known opponent of the English crown.
Bolton was a known opponent of the U.N. with a stated view that "it wouldn't make a bit of difference" if the U.N. building in Manhattan lost 10 of its 38 floors.
It is a stunning reversal of opinion for Clinton, a well known opponent of the use of private security companies and a political appointee who has openly discussed taking steps to eliminate them.
The college said Wednesday that Dr. Corvino has been invited for next spring to debate Sherif Girgis, a nationally known opponent of gay marriage.
"I can't say that there is". Professor Sargent, a widely known opponent of the plan, has appeared against the proposal on numerous occa sions.
Though it may seem logical for Mr. Gore to try to bathe his less well known opponent in a negative light, the strategy carries clear risks, say independent analysts and some Democrats as well.
If good enough, go up to an unknowing (or Knowing) opponent and get a no scope.
