'Mischievous' in the Bible

Therefore let us keep our festival not with old yeast nor with the yeast of what is evil and mischievous, but with bread free from yeast--the bread of transparent sincerity and of truth.

For this reason, if I come, I shall not forget his conduct, nor his idle and mischievous talk against us. And he does not stop there: he not only will not receive the brethren, but those who desire to do this he hinders, and excludes them from the Church.