around the neck; neck measurement
Refers to the area around the neck or the measurement of the neck circumference, commonly used in clothing sizes.
This shirt is tight around the neck.
スーツを注文するときは首回りのサイズを測ります。
When ordering a suit, I measure my neck size.
Compound of 首 (kubi, 'neck') and 回り (mawari, 'circumference; around').