The US actress and the musician issued a joint statement containing the phrase when they announced their split.
She told the British Vogue magazine that they were introduced to the phrase by their therapist “who helped us architect our new future”.
“Frankly, the term sounded a bit full of itself, painfully progressive and hard to swallow,” Paltrow said.
She added: “I was intrigued, less by the phrase, but by the sentiment.
“Was there a world where we could break up and not lose everything?
“Could we be a family, even though we were not a couple?”
She added that the “public’s surprise gave way quickly to ire and derision”.
“A strange combination of mockery and anger that I have never seen,” she said.
“I was already pretty tattered from what had been a tough year.
“Frankly, the intensity of the response saw me bury my head in the sand deeper than I ever had in my very public life.”
Paltrow said the pair, who separated in 2014, “tried everything” to make their situation work.
“We didn’t want to let anyone down. We desperately didn’t want to hurt our children. We didn’t want to lose our family,” she said.
Despite their best efforts Paltrow said she realised they had “diverged”, adding: “We’d never find ourselves together in that way again.”
She said that her and Martin were “close” and shared the same sense of humour and taste in music but “never fully settled into being a couple”.
“We just didn’t quite fit together,” she said.
“There was always a bit of unease and unrest. But man, did we love our children.”
Paltrow, who is now married to TV producer Brad Falchuk, has two children with Coldplay frontman Martin.
