I leaned back in my chair.

我仰靠在椅背上。

《牛津词典》

I leaned back to get a better view, and fell off the chair.

我向后仰想看得清楚些，可却从椅子上摔了下来。

youdao

As I slid into the front seat of my car that afternoon, I leaned back, exhausted from the emotional trauma.

那天下午，我钻进汽车前座坐下来，感情的创伤令我身心憔悴。

youdao

Made bold by excitement, I leaned over the boat's back rail, my face inches from the water to snap the shark's picture.

WSJ: Fishing for Shark in Destin, Fla.