The disgraced celebrity publicist, aged 73, is on trial at Southwark Crown Court accused of indecently assaulting her in his London office in the 1980s, which he denies.
He was jailed for eight years in May 2014 after being convicted of a number of charges under Operation Yewtree, the Met Police investigation set up after the Jimmy Savile scandal.
The woman, who cannot be named for legal reasons, said: “He unzipped his trousers and came towards me. He said, ‘let’s have some fun’, or something along those lines, ‘let’s have a bit of fun’.
“I said, ‘I don’t want to’. He took my hand and put it on him.”
She added: “I was worried he was either going to rape me or kill me. I didn’t know what would happen next. It was something I had never experienced before and was worried what was coming next.”
She said she did not report the incident earlier because she was “ashamed”, adding: “I didn’t think I would be believed or that anyone would do anything. He was so powerful... I’m nobody.”
Clifford is accused of assaulting the girl at his Mayfair offices in New Bond St between October 1981 and May 1982.
She said he also made “smutty” jokes about her with late comedian Lennie Bennett. “They were like schoolboys,” she told the jury. “He would say things like, ‘we will get you to take your top off by the end of the day’.”
She was accused of making up the allegation after apparently reading in the news Clifford’s victims could be entitled to up to £200,000 (€240,000) compensation.
Sarah Forshaw, defending, asked: “What was it that made you report something that had happened 34 years ago? Was it the money?”
“No, it wasn’t the money,” the woman replied. “I would say I’m a victim of Max Clifford because he did what he did — that’s why,” she added.
She was also quizzed about the size of Clifford’s penis. Ms Forshaw said: “In the last trial the size of Mr Clifford’s penis became the source of much hilarity because of conflicting accounts — it was called a micro penis and absolutely massive. It was reported on the news.”
She added: “It was measured and was actually an average-sized penis. What size are you going to tell the jury his penis was?” The woman answered: “I’m not aware — I wasn’t looking and didn’t have anything to compare it to. I saw it when he came towards me... it was just... not big but it wasn’t erect.”