首筋

1. Origins, structure, and basic meaning

• Structure: 首筋 is read as くびすじ and is a noun for the nape or the line along the back and side of the neck.
• Basic usage: Cold wind touching it appears in 首筋に当たる, while stiffness appears in 首筋がこる.

2. Common pitfalls and similar expressions

• A particular area of the neck
  • It identifies the back or side line where wind may touch or muscles may become stiff, rather than the whole neck.
• Difference from 首
  • 首 broadly denotes the neck, whereas 首筋 emphasizes the nape area running down toward the shoulders.