鈍る

1. Origins, structure, and basic meaning

• Structure: 鈍る, read にぶる, is a verb for becoming sluggish or dull.
• Basic usage: It applies to movement and a tool's sharpness.

2. Common pitfalls and similar expressions

• Two subjects
  • 体の動きが鈍る means movement becomes sluggish.
  • 刃が鈍って describes a blade grown dull.
• Inflection
  • The te-form is 鈍って.
  • The nonpast form is 鈍る.