繭

1. Origins, structure, and basic meaning

• Structure: 繭 is read as まゆ and can mean “cocoon” or “silkworm cocoon”, depending on context.
• Basic usage: The examples show a white cocoon on a branch and silk thread drawn from silkworm cocoons.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It is the casing a larva forms before pupation; 蚕の繭 specifically supplies the filament used for silk.