black out v.眼前发黑；用墨等涂掉；熄灭灯光；查禁；昏厥；对…实施灯火管制。
blackout n. [ C ] (UNCONSCIOUSNESS)
= a short period when someone suddenly becomes unconscious暂时晕倒；暂时失去知觉。
常用意思还有“断电；灯火管制；（新闻的）封锁；（广播的）中断”。

【例句】
He can't drive because he suffers from blackouts.
因为暂时性昏迷他无法开车。

The date on the letter had been blacked out.
信上的日期被涂掉了。