Meaning & use
on watch
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Meanings
phrasefixed phrasemilitary
Responsible for staying alert and guarding or monitoring something during a set period, especially on a ship or in the military.
Grammar: Used after a verb: be on watch, go on watch.
Patterns
- be on watch
- go on watch
- stand on watch
Two sailors were on watch while the rest of the crew slept.
I go on watch at midnight and finish at four.
The guards stayed on watch all night near the gate.
phrasefixed phrasefigurative
Paying close attention and ready to notice any sign of trouble or a particular thing.
Grammar: Often followed by for: on watch for danger.
Patterns
- be on watch for something
- stay on watch
Hikers should be on watch for snakes along the trail.
Parents were on watch for signs of the flu.
The nurse stayed on watch for any change in the patient.
Common combinations
- be on watch
- Who is on watch tonight?
- go on watch
- The second mate goes on watch at six.
- on watch for
- Be on watch for black ice.
- stay on watch
- We stayed on watch until dawn.
Synonyms and how they differ
- on guard
- On guard stresses being ready to defend against a threat, while on watch can also mean simply observing.
- on duty
- On duty means working a shift of any kind, while on watch means specifically keeping lookout.
- on the lookout
- On the lookout is for finding a specific thing, such as a bargain, and carries a less formal sense of duty.
- vigilant
- Vigilant is a single adjective for careful attention and is more formal.
Opposites
Word family
Commonly confused: on watch or on the watch?
on watch vs on the watch
On the watch is a variant of on watch used with for, as in on the watch for thieves.
Practice
The captain asked who was ___ at three in the morning.
Choose one answer.
On watch is the fixed phrase for being responsible for the lookout. The other prepositions do not form a standard phrase.
Make it your own
Write a sentence using “on watch”, then check it and compare it with the examples above.