noun
A matching jacket and pants set originally for athletics, now also worn as casual wear. The Japanese term is a direct loan from English.
彼はジムに行くとき、いつもトラックスーツを着ている。
He always wears a tracksuit when he goes to the gym.
新しいトラックスーツを買ったので、ランニングが楽しみだ。
I bought a new tracksuit, so I'm looking forward to running.