NORRISTOWN, Pa. — Bill Cosby’s star defense witness, a veteran academic adviser who works at his alma mater, Temple University, testified here Wednesday that the woman who has accused Mr. Cosby of sexual assault had once remarked to her how it would be easy to fabricate such a charge to frame a celebrity and get money.

The adviser, Marguerite Jackson, said Andrea Constand, who was once the director of operations for Temple’s women’s basketball team, made the comment while they were watching television in a hotel room they shared on a trip by the team for a game in Rhode Island.

“She said it did not happen,” Ms. Jackson told the jury at the Montgomery County Courthouse.

Ms. Constand testified this week that while Ms. Jackson’s name sounded familiar, she had always roomed alone on trips.

But from the witness stand here, Ms. Jackson said she had shared a room with Ms. Constand for away games on two or three occasions. One time, in February 2004, she said Ms. Constand told her she had been assaulted by a celebrity, after seeing a clip on television about another, unnamed star who had been so accused.