A person to talk with; someone you converse with or confide in.
転勤で引っ越して、まだ話し相手がいなくて寂しい。
I moved for a job transfer and I feel lonely because I don't have anyone to talk to yet.
母は私の一番の話し相手で、何でも相談している。
My mother is my best confidant; I consult her about everything.
オンラインで話し相手を募集して、毎晩英会話の練習をしている。
I looked for conversation partners online and practice English every night.