Meaning & use
be slack-jawed
Last updated
Meaning
phrasefixed phraseinformal
to have your mouth slightly open because you are very surprised, shocked, or amazed
Grammar: Often used after 'leave' or 'stand': leave someone slack-jawed, stand slack-jawed. It describes a state, not an action.
Patterns
- be slack-jawed at something
- leave someone slack-jawed
- stand slack-jawed
The audience was slack-jawed at the magician's final trick.
He stood slack-jawed as the car exploded.
The news left everyone slack-jawed.
Common combinations
- slack-jawed amazement
- They watched in slack-jawed amazement.
- leave someone slack-jawed
- The ending of the film left us slack-jawed.
- slack-jawed stare
- He gave me a slack-jawed stare.
Synonyms and how they differ
- open-mouthed
- Very similar, but can also mean 'eager' or 'gaping' in other contexts; 'slack-jawed' specifically suggests the jaw has dropped in shock.
- gobsmacked
- British informal; it means extremely surprised but does not describe the physical open mouth.
- astonished
- More formal and general; it does not include the physical description of the jaw.
Opposites
Word family
- slack-jawed adjective
- Having the mouth open in surprise.
Commonly confused: be slack-jawed or slack?
be slack-jawed vs slack
As an adjective, 'slack' means loose or not tight. 'Slack-jawed' is a compound adjective meaning having a loose, open jaw.
Practice
The audience sat ___ as the acrobat performed the dangerous stunt.
Choose one answer.
'Slack-jawed' is the correct adjective form. 'Slack-jaw' is not an adjective. 'Slackly jawed' is not a standard phrase. 'Slack jawing' is not used as an adjective.
Make it your own
Write a sentence using “be slack-jawed”, then check it and compare it with the examples above.