Four high school classmates of Supreme Court nominee Brett Kavanaugh have claimed that the phrase "Devil's Triangle" in Kavanaugh's yearbook is a drinking game and not a reference to sexual activity, as has been claimed by some opponents of Kavanaugh.

The phrase took center stage when Sen. Sheldon Whitehouse, D-R.I., asked Kavanaugh its meaning during a hearing last week.

"It's a drinking game," responded Kavanaugh, who asked Whitehouse if he had "ever played quarters?", a reference to another drinking game.

In a letter released by Republicans on the Senate Judiciary Committee, Delancey Davis, Bernard McCarthy Jr., Paul Murray and Matthew Quinn said the game was a variation on quarters.

"When we played 'Devil’s Triangle,' four people sat at a table. On the table, three small glasses of beer were arranged next to one another to form a triangle. Each of the four participants took turns being the “shooter," they wrote. "The shooter attempted to bounce a quarter into one of the glasses. If the quarter landed in one of the glasses, the person at the table sitting nearest that glass had to drink the beer."

The quartet added that while they do not remember how the game came to be called "Devil's Triangle," they were adamant that "none of us used the phrase ... in our yearbook to refer to any kind of sexual activity."

"If the phrase 'Devil's Triangle' had any sexual meaning in the 1980s, we did not know it," they concluded.

The committee also released a letter from two men who roomed with one of Kavanaugh's high school classmates while they were undergraduates at Boston College. The men, Greg Aceto and Bill Van Pelt IV, said that Kavanaugh's classmate Matthew Quinn had taught them how to play "Devil's Triangle" and added that they did not understand it to have any sexual meaning.

Some opponents of Kavanaugh's nomination have interpreted the phrase to refer to a three-way sexual encounter. On Wednesday, Jamie Roche, Kavanaugh's freshman year roommate at Yale told CNN that he heard Kavanaugh use the term to refer to sexual activity.

Fox News' Mike Emanuel contributed to this report.