watchful

形容词 watchful:

1. carefully observant or attentive; on the lookout for possible danger
   同义词：argus-eyed, open-eyed, vigilant, wakeful
2. experiencing or accompanied by sleeplessness- Shakespeare
   同义词：insomniac, sleepless

1. A watchful nurse tending a critically ill patient.
   照顾一个重病号的谨慎的护士
2. Be sure to be watchful or alert.
   必须留神，千万要提防。
3. We should be watchful of computer viruses.
   我们应该警惕计算机病毒。
4. The guard should be watchful during the night.
   警卫在黑夜里也应该警醒。

watch.ful

adj.（形容词）
Closely observant or alert; vigilant:
警惕的：密切注意或戒备的；警惕的：
例句：
kept a watchful eye on the clock.See Synonyms at aware ,careful
注意时间参见 aware,careful

Archaic Not sleeping; awake.
【古语】 不眠的；醒的

【引伸】
watch.fully
adv.（副词）
watch.fulness
n.（名词）