shake

1. Origins, structure, and basic meaning

• Structure: 振 has 10 strokes and the on-reading しん. 振る (ふる) and 振り向く (ふりむく) describe waving something or turning to face a direction.
• Basic usage: 振る means waving a flag or shaking one's head; 振り向く means looking back or turning toward a sound.

2. Common pitfalls and similar expressions

• Shaking one's head and turning to look
  • 旗を大きく振ると appears where waving a flag in a wide arc is followed by the ship starting to move. 答えず、静かに首を振った means quietly shook one's head without answering.
  • 名前を呼ばれて思わず振り向いた means instinctively turned around when one's name was called. こちらを振り向く describes the dog noticing footsteps and turning to look this way.