To restore a file to a previous condition by removing changes in the reverse chronological order from which the changes were originally made.

• （作动词用）表示把一个经过多次修改过的文件恢复到原先的状态，这种恢复的过程从时间顺序上看，与原先修改文件的过程相反，依次把各次修改的内容清除掉。