A good conversationalist; someone skilled at talking who can make conversation flow and engage listeners.
彼女は話し上手で、初対面でも会話が弾む。
She's a good conversationalist, and conversation flows even on first meetings.
プレゼンが苦手だったが、練習して話し上手になった。
He wasn't good at presentations, but with practice he became a good speaker.
彼は冗談を交えて話すので、とても話し上手だ。
He mixes in jokes when he talks, so he's very good at speaking.