尾びれ

1. Origins, structure, and basic meaning

• Structure: 尾びれ is read as おびれ and means “tail fin”.
• Basic usage: The examples show a fish’s propulsive tail fin and an injury on an aquarium fish’s tail fin.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It is the fin at the rear of a fish used for propulsion and steering, distinct from side fins such as 胸びれ.