If something such as an action or an event underscores another, it draws attention to the other thing and emphasizes its importance.
例句
The Labor Department figures underscore the shaky state of the economic recovery...劳工部的数据进一步印证了经济复苏状况的不稳定。The rash of accidental shootings underscores how difficult it will be to restore order here.一连串的意外枪击事件凸显了恢复该地区的秩序有多困难。
VERB
在（字词、句子等）下画线
If you underscore something such as a word or a sentence, you draw a line underneath it in order to make people notice it or give it extra importance.
例句
He heavily underscored his note to Shelley.他在给谢利的便条内容下面重重地画了线。