May delayed a crucial parliamentary vote on her withdrawal deal last week as it faced nearly certain defeat in the House of Commons.
He said he was "completely opposed to the use of sexist or misogynist language".
Speaker John Bercow said he had consulted "lip speakers" - people who can hear but interpret for deaf people - and they believed Mr Corbyn probably did deliver the slur, but no-one could be "100 per cent" certain.
Footage of the "stupid" comment quickly went viral on social media, watched by MPs on their phones as they sat in the Commons chamber - and one of them asked May what she thought.
Jeremy Corbyn has become embroiled in a misogyny row after being accused of mouthing "stupid woman" at Prime Minister Theresa May during Prime Minister's Questions.
Mr Corbyn's claim "most of our media" didn't report the death of the homeless man accompanied headlines of the "stupid woman" row as featured in The Times, the Daily Mail and the Independent website.
Did Jeremy Corbyn call Theresa May a 'stupid woman'? (VIDEO)
Labour's biggest union backer says its MPs should work across party lines to save Brexit in parliament as he intensified his opposition to a second referendum.
Labour former foreign secretary Margaret Beckett said it looked like an "orchestrated riot" by Conservative MPs.
The remark was not picked up on microphones, but politicians from both sides of the House were in little doubt what he said.
Ms Abbott told the programme: "Tory MPs put on a display yesterday that Hackney primary school children would have been ashamed of". "As I understand it, he said 'stupid people, '" the spokesperson said.
But he triggered a furious response from a slew of female MPs, including Commons leader Andrea Leadsom after refusing to take immediate action because he had not seen the incident.
She said: "This is just the latest in a long line of misogynistic behaviour from Corbyn and his top team". Bercow reacted with barely contained anger, wagging his finger at Ford and denying the allegation against him.