動詞 back out:

1. move out of a space backwards
   同義詞：back out
2. make a retreat from an earlier commitment or activity
   同義詞：retreat, pull back, back out, back away, crawfish, crawfish out, pull in one's horns, withdraw

1. He paid it back out of his earning.
   他用掙的錢把它償還了。
2. He put his back out badly, falling down the stairs like that.
   他那樣從樓梯上跌了下來，使背椎骨嚴重錯位。