股下

1. Origins, structure, and basic meaning

• Structure: 股下, read またした, is the inseam or inside-leg measurement.
• Basic usage: 股下の長さを測る measures the dimension before purchase; 股下が長い explains why the hems need alteration.

2. Common pitfalls and similar expressions

• Measurement name and length judgment
  • The noun already identifies the inseam dimension; の長さ spells it out, and it does not mean a person's full height.