Elizabeth Warren has called Donald Trump a host of unflattering words, from “weak,” to “reckless,” to “embarrassing.” Now she’s revealed her favourite dirty word of all – and it’s equally family friendly.

In an interview with CBS News, reporter Chip Reid asked the senator from Massachusetts for her curse word of choice. Her response: “Poop.”

Pressed by Mr Reid, the senator gamely laid out her reasoning for those who don’t believe “poop” is a curse word.

“Have you ever seen a woman like me look you straight in the face after you’ve finished some long explanation of something and then just said, ‘Poop’?” she asked. “Try it.”

Ms Warren has earned a reputation as a “fighter” for her repeated critiques of Mr Trump, and for a now-infamous interaction with Senate Majority Leader Mitch McConnell on the Senate floor.

During the February confirmation hearing for Attorney General Jeff Sessions, Ms Warren read aloud from a letter written by Coretta Scott King. The letter denounces Mr Sessions’ conduct as United States Attorney in Mobile, Alabama.

Mr McConnell invoked a little-known Senate rule to silence her testimony, but inadvertently gave Democrats a rallying cry with his justification: “She was warned. She was given an explanation. Nevertheless, she persisted.”

Ms Warren’s Monday interview on CBS is part of a nationwide tour to promote her new book, “This Fight Is Our Fight: The Battle to Save America's Middle Class.” Her events promotional events in Western Massachusetts, Washington D.C.'s and Los Angeles have all sold out.

The book tour creates a convenient platform for Ms Warren to get her message out before the 2018 midterm elections – and some believe she could be setting herself up for a presidential run in 2020.