外貨

1. Origins, structure, and basic meaning

• Structure: 外貨, read がいか, is foreign currency relative to one's domestic currency.
• Basic usage: 外貨と自国通貨を分ける contrasts the categories; 残った外貨を入れる stores money left after travel.

2. Common pitfalls and similar expressions

• Foreign currency relative to domestic currency
  • The category depends on the reference country, and explicit 自国通貨 establishes that contrast.