what is the definition of council of treat?

Answer 1

I think you are having trouble finding it because it is spelled "Council of Trent"

Try http://en.wikipedia.org/wiki/Council_of_Trent

It was, basically, the Roman Catholic Church responding to the challenges that protestant reformers were making about 500 years ago. pretty interesting reading if you like history.

Answer 2

You want to ask about the Council of Trent. It was a council of the Church. It was not an ecumenical council, because we do not have those anymore, but it was the beginning of the Counter-Reformation.