能说会道 is a four-character idiom that describes someone who is very articulate, eloquent, and skilled at expressing themselves or persuading others through speech. The literal meaning — 'can speak, know how to say' — may sound neutral, but the idiom is generally positive or mildly admiring, though it can carry a slight hint of 'smooth talker' depending on context. It's used as a predicate (那个人很能说会道) or as a descriptive attribute (一个能说会道的销售).