微動

1. Origins, structure, and basic meaning

• Structure: The spelling is 微動, read びどう, and it combines 微, meaning minute, with 動, meaning movement.
• Basic usage: The basic sense of 微動 is a movement or tremor so slight that it may be difficult to notice.

2. Common pitfalls and similar expressions

• Slight motion and emphatic immobility
  • The forms are 微動だにしなかった and 微動. The first idiomatically emphasizes not moving even slightly; the second names a small movement that was actually detected.
• A soldier's posture and ground monitoring
  • 兵士は物音がしても微動だにしなかった。 — The soldier did not move at all despite hearing a noise.
  • 観測装置が地面の微動を記録した。 — The monitoring device recorded slight movements in the ground.