"smooth," occurs in Luk 3:5, figurative of the change in Israel from self-righteousness, pride and other forms of evil, to repentance, humility and submission. In the Sept., Gen 27:11, 1Sa 17:40, Pro 2:20, Pro 12:13, Pro 26:23, Isa 40:4.
Note: Chrestologia (chrestos, "good," lego, "to speak") is rendered "smooth ... (speech)," in Rom 16:18, RV (AV, "good words").