noun
shoulder strap
Specifically the strap that goes over the shoulder on clothing like dresses, camisoles, or bags.
このワンピースは肩紐が細すぎて不安だ。
The shoulder straps on this dress are so thin I'm worried.
肩紐がずり落ちないように調節してください。
Please adjust the shoulder straps so they don't slip off.
A broader loanword for any strap, including those on bags, cameras, or watches. 肩紐 is specifically a shoulder strap on clothing.
Compound of 肩 (かた, 'shoulder') and 紐 (ひも, 'string, cord').