Stephen Colbert used a harsh profanity to describe President Trump on Wednesday during an appearance on stage at Michael Moore's one-man Broadway play, "The Terms of My Surrender."

Mr. Colbert, the host of "The Late Show" on CBS, was one of the special guests whom Mr. Moore regularly invites to take part in the production. As the two men sat in armchairs with a large American flag illuminated in the background, Mr. Moore asked Mr. Colbert at one point, "How do you carry on now?" — a reference to the liberal late-night host's approach to the Trump presidency.

Mr. Moore added, "Your ability to use satire and humor to say the emperor has no clothes is profound every single night."

Laugh through the fear, Mr. Colbert replied.

"Trump keeps summoning monsters of abstraction — things that aren't real — they're extensions of the ordinary, fears that you have that he plays on," Mr. Colbert said.

"He wants to brush people into a corner where he can shine his feeble, fucking anemic firefly of a soul," Mr. Colbert continued, inching his two pointer fingers close together.