'Smooth' in the Bible

Every valley will be lifted up, and all the mountains and hills made low, and the twisted will be made straight, and the rough ways smooth;

For such people are not servants of the Lord Christ, but of their stomachs; and by their smooth and well-said words the hearts of those who have no knowledge of evil are tricked.

For it is common knowledge among you that we never made use of smooth-sounding false words, and God is witness that at no time were we secretly desiring profit for ourselves,