That's definitely not a way that I've heard 'heresy' used. From Wikipedia:

Heresy is an introduced change to some system of belief, especially a religion, that conflicts with the previously established canon of that belief.

In the Catholic tradition, heretics (people committing heresy) were condemned for leading people to believe that Catholicism is about something that it is not, and therefore putting their souls in danger.

Perhaps in the definition you gave above, you were referring to the attitude the Church had towards heresy, rather than heresy itself?

Also, your definition doesn't fit what Alicorn suggested above. It might if you replace 'idea' with 'utterance' and understand 'denounce' to not mean 'reject as false'.