The liberal TV personality made the comment in an interview with ABC News' Jake Tapper Thursday, the New York Daily News reported.
The two were talking about the media firestorm that occurred when conservative talk-show host Rush Limbaugh called Georgetown University student Sandra Fluke a "slut" and a "prostitute" after she spoke to Congress about the need to expand birth-control coverage.
Maher explained why he thinks Limbaugh's remarks about Fluke are different from offensive language he himself has used to describe Palin, the 2008 Republican vice presidential nominee. For one, he pointed out, he is a comedian, while Limbaugh is a political commentator.
Maher also said Limbaugh "went after a civilian about very specific behavior, that was a lie, speaking for a party that has systematically gone after women's rights all year, on the public airwaves," the Daily News said.
"I used a rude word about a public figure who gives as good as she gets, who's called people 'terrorist' and 'un-American.' ... The First Amendment was specifically designed for citizens to insult politicians. Libel laws were written to protect law students speaking out on political issues from getting called whores by OxyContin addicts."
Limbaugh has since apologized for his comments, but several advertisers pulled their commercials from his show.