one sleeve
Refers to a single sleeve of a garment, often used in contexts like sewing, clothing descriptions, or when one sleeve is missing or different.
片袖だけ色が違うシャツを見つけた。
I found a shirt where only one sleeve is a different color.
着物の片袖を直してもらった
I had one sleeve of the kimono repaired.
Compound of 片 (kata, 'one side') and 袖 (sode, 'sleeve').