watchful

adjective

watch·​ful ˈwäch-fəl 

ˈwȯch-

1

archaic

a

: not able or accustomed to sleep or rest : wakeful

b

: causing sleeplessness

c

: spent in wakefulness : sleepless

2

: carefully observant or attentive : being on the watch

watchfully

ˈwäch-fə-lē 

ˈwȯch-

adverb

watchfulness noun

Synonyms of watchful

• alert
• vigilant
• awake
• careful

Choose the Right Synonym for watchful

watchful, vigilant, wide-awake, alert mean being on the lookout especially for danger or opportunity.

watchful is the least explicit term.

the watchful eye of the department supervisor

vigilant suggests intense, unremitting, wary watchfulness.

eternally vigilant in the safeguarding of democracy

wide-awake applies to watchfulness for opportunities and developments more often than dangers.

wide-awake companies latched onto the new technology

alert stresses readiness or promptness in meeting danger or in seizing opportunity.

alert traders anticipated the stock market's slide

Examples of watchful in a Sentence

We need to be more watchful of our children.

The hotel is being built under the watchful eye of its architect.

Recent Examples on the Web

But the senior royals of today still keep a watchful eye on their guests. —Stephanie Nolasco , Ashley Papa, FOXNews.com, 28 Mar. 2026

Sign-toting protesters walked down Colorado Boulevard under the watchful eye of Pasadena police officers on motorcycles. —Staff and Wire Reports, Daily News, 28 Mar. 2026

Article continues below Gnanamoorthy kept a watchful eye on the weather forecast as the eclipse drew closer, tracking cloud fronts that could make or break his expedition. —Anthony Wood, Space.com, 25 Mar. 2026

Danae kept a watchful eye over the young ones. —David Gleisner, Outside, 24 Mar. 2026

Word History

First Known Use

15th century, in the meaning defined at sense 1a

Phrases Containing watchful

• keep a watchful eye on (someone or something)
• under the watchful/vigilant eye of

Kids Definition

watchful

adjective

watch·​ful ˈwäch-fəl 

ˈwȯch-

: continually on the lookout especially for danger

watchfully

-fə-lē 

adverb

watchfulness noun