ENGLISH
REFERENCE

watchful

adj.
B2 Upper Intermediate US //ˈwɑtʃfəɫ// UK //wˈɒtʃfəl// watch·ful

adj. paying close attention to what is happening around you. You do this to stay safe or to make sure nothing goes wrong.

adj. characterised by careful observation and alertness to potential danger or change. Often used to describe a state of protective or cautious monitoring.


SIMPLE

The mother kept a watchful eye on her children at the park.

CONTEXTUAL

Security guards remained watchful throughout the night to ensure no unauthorized person entered the building.

COMPLEX

Under the watchful gaze of the international community, the two nations began the delicate process of negotiating a lasting peace treaty.

Synonyms
Antonyms
Origin

From Middle English waccheful, equivalent to watch + -ful. Compare West Frisian waaks (“watchful”), Dutch waaks, waakzaam (“watchful”), German wachsam (“watchful”), Swedish vaksam (“watchful”).

Usage

Commonly used in the fixed phrase 'keep a watchful eye on'. Often follows linking verbs like 'remain', 'stay', or 'be'.

© 2026 English Reference