watchful

To be watchful is to be alert and aware. A watchful dog might keep an eye on the sidewalk in front of your house all afternoon.

The adjective watchful is good for describing someone who keeps an attentive eye on things. A watchful teacher, for example, knows immediately when a student is being teased, and a watchful driver is quick to stop for a pedestrian crossing the street. When you're on the lookout, you're being watchful. The word comes from the Middle English waccheful, which used to have an alternate meaning of "wakeful" or "sleepless."

Definitions of watchful
1

adj engaged in or accustomed to close observation

Synonyms:
alert
argus-eyed, open-eyed, vigilant, wakeful
carefully observant or attentive; on the lookout for possible danger
fly
(British informal) not to be deceived or hoodwinked
heads-up, wide-awake
fully alert and watchful
lidless, sleepless
always watchful
wary
marked by keen caution and watchful prudence
awake
not in a state of sleep; completely conscious
lively
full of life and energy
Antonyms:
unalert, unvigilant, unwatchful
not alert to what is potentially dangerous
unwary
not alert to danger or deception
show more antonyms...

adj experiencing or accompanied by sleeplessness

“"twenty watchful, weary, tedious nights"- Shakespeare”
Synonyms:
insomniac, sleepless
awake
not in a state of sleep; completely conscious

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