watchful

/ˈwɑtʃfʊl/

/ˈwɒtʃfʊl/

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. adjective

   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
2. adjective

   experiencing or accompanied by sleeplessness
   “"twenty watchful, weary, tedious nights"- Shakespeare”

   synonyms: insomniac, sleepless

   awake

   not in a state of sleep; completely conscious