A spokeswoman says Illinois' U.S. Sen. Mark Kirk has apologized after being caught on a hot microphone using a word considered disparaging to women.

Kirk called Republican senator and presidential candidate Lindsey Graham a "bro with no ho." The remarks were heard Thursday as a Senate panel conducted a roll call vote. The South Carolina senator is a lifelong bachelor who's joked he could have a "rotating first lady" if elected.

Later, in a muffled part of the recording, Kirk is heard suggesting that's how urbanites would say it. Kirk is a suburbanite.

Kirk spokeswoman Danielle Varallo says it was a joke between friends, adding Kirk has apologized.

The campaign for Kirk's potential Democratic 2016 challenger, Congresswoman Tammy Duckworth, deemed Kirk's comments "as offensive as it is unfunny."

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