二重

1. Origins, structure, and basic meaning

• Structure: 二重 combines 二 with 重, indicating layering, to mean two layers or a double structure.
• Basic usage: It describes layered structures such as windows or tape; 二重にする means making something double-layered.

2. Common pitfalls and similar expressions

• Two layers and twice as much
  • 二重 focuses on layering or duplication, while 二倍 expresses a ratio of quantity or size.
• Reading and usage
  • The reading for this entry is にじゅう. The same spelling, read ふたえ, can refer to a double eyelid, so the context helps distinguish the uses.