PFA chairman Carlisle criticised the pair after they, among other players, refused to wear 'Kick It Out' t-shirts in protest at what they believed to be inadequate action against racism
Carlisle was asked by The Guardian what he meant by that word: "Erm. I suppose it basically means 'cowardly'," he said.
"And that was how I felt at the time," he continued to The Guardian. "I felt that players, I felt that the guys did something that was very public but then weren't willing to actually step forward and be accountable for what they did and state the reasons why."
"I don't think that they're all shithouses. It's a very, very strong word isn't it. But I was very, very angry at the time. I think players should have more courage to stand up for what they believe and if they feel strongly about something they should speak out and have the courage to do that."
Carlisle was then asked if he expressed those views to the Ferdinands at the time "I didn't say it to them personally, to their faces," he said.
"But I made it clear in the interviews and in the meetings and in passing on information that [their actions] needed to be explained. I made that clear, and I stated it publicly. There's nothing for me to, I don't think, I don't feel guilty about writing that part. Not at all.
"It's inflammatory writing, it's emotional writing. I think anybody would be offended if they were called cowardly."
When it was put to him by The Guardian that calling men who had been victims of racial abuse 'sh*thouses' was strange, Carlisle said: "I didn't call them sh*thouses for being victims of racial abuse, and I didn't call Rio and Anton individually two sh*thouses. I said I was angry and frustrated at the players who didn't wear the T-shirts, of which there were many, not just Rio and Anton."
In his book, serialised in The Daily Mail this week, Carlisle said: 'Rio and Anton Ferdinand were among a group of high-profile abstainers along with Joleon Lescott, who has not worn one since Newcastle's Turkish midfielder Emre was cleared of racially abusing his Everton team-mate Joseph Yobo, and Jason Roberts.
'At least Jason was vocal about his reasons. I don't mind people disagreeing but at least say why.
'Jason apart, the Premier League 'big' players happily throw in a grenade but do nothing when it explodes, nothing other than appear to hide behind their advisers.
'That's because they are s***houses. They have made their 'statement' for all to see but how many are prepared to stand in front of the cameras and be counted?'
"I didn't say it to them personally, to their faces,"...who's the coward again?- ishtiano