Glenda Partridge was dismissed from the pound;2,400-a-term junior school at Arnold Lodge school, in Leamington Spa, after two members of staff complained about her alleged behaviour.
They accused her of whispering "stupid cow" and "stuck-up bitch" to a colleague during a staff meeting, in reference to Elizabeth Hickling, principal, and Lucy Wheeler, vice-principal.
England's General Teaching Council was told she made derogatory comments about the senior management team on a number of occasions.
Mrs Partridge, of Earlsden, Coventry, who has a 24-year unblemished record, denied the allegations and said her dismissal was a smokescreen to replace her with a cheaper teacher.
Mrs Hickling, who became head in September 2003, said the school's site manager and her secretary told her that they had overheard Mrs Partridge "bitching" about her in January 2004.
Chris Newman, the site manager, whose father owns the school, said he had listened to Mrs Partridge making a stream of derogatory comments during a meeting.
Christine Dixon, the principal's personal assistant, told her she had watched Mrs Partridge act out a silly walk poking fun at the principal, pretending to vomit outside Mrs Hickling's office, and pulling faces.
Mrs Hickling said: "I found the comments distasteful, stressful and difficult to deal with."
The principal launched an investigation, taking statements from teachers, and ordered Mrs Partridge to attend a disciplinary hearing. She was sacked after being found guilty of unprofessional conduct.
Mrs Partridge appealed against the decision and lost. She later filed a claim to an employment tribunal for unfair dismissal, but settled for an undisclosed payment from the school. She could be struck off as a teacher if found guilty of unacceptable professional conduct by the GTC.
She said the allegations had been fabricated. "I feel like I have been singled out. There has been the odd day when I've had a grumble, but no more than any other member of staff."
Mrs Partridge said she had forged a good relationship with fellow teachers and parents after her appointment in April 2000. But she became suspicious after failing to receive her annual salary rise in 2003, when other staff members did. Following her dismissal, her position was not filled and the teaching structure was reorganised. She said: "I was the third highest-paid member of staff and I think that was a problem. I honestly cannot think what else it can be."
The hearing continues.