足

1. Origins, structure, and basic meaning

• Structure: The body-part noun 足 (あし) can denote either the foot or the leg.
• Basic usage: 足を入れる can focus on putting one's feet into water, while 足が疲れる refers more broadly to tired legs.

2. Common pitfalls and similar expressions

• Foot and leg
  • English must choose foot or leg from the body-part context rather than using one translation in every case.