To turn one's face or body around; to look back or glance over one's shoulder in response to a sound or someone calling.
後ろから声がしたので、思わず振り向いた。
A voice called from behind, so I couldn't help turning around.
子どもがお菓子の袋の音に振り向いた。
The child turned around at the sound of the snack bag.
彼は私のことを気にせず、まったく振り向かなかった。
He didn't care about me and didn't turn to look at all.