This is the 7382nd most frequent Japanese word.
仰け反る
To bend or lean backward.
Here, "仰け反る" implies an action of physically or emotionally recoiling due to surprise or shock.
彼の突然の発言に仰け反った。
I recoiled at his sudden statement.
In this usage, "仰け反る" describes the instinctive backward movement caused by fear or shock.
その恐ろしい場面に仰け反るほど驚いた。
I was so shocked at the terrifying scene that I recoiled.
Here, "仰け反る" conveys a physical leaning back due to excitement or enthusiastic reaction.