1590s, "support;" 1640s, "retreat;" verbal noun from back (v.). Physical sense of "anything forming a backing to something else" is from 1793. Meaning "musical accompaniment" is recorded from 1940.
权威例句
1. Make a point of backing up your files at regular intervals.
一定要定期备份文件。
2. He's backing away from the policies and style of his predecessor.
他正脱离其前任的政策和风格。
3. "I wouldn't know about that, Miss," the woman said, backing away.
“我不想知道那件事情,小姐,”这个女人一边后退一边说。
4. I eventually got financial backing, but it was a slog.
我最终得到了经济支持,但这得来不易。
5. Crucially, though, it failed to secure the backing of the banks.