in a heartbeat
Proposed by a contributor, not yet supported by evidence.
Meaning · English
very quickly or immediately
Literally: in the time it takes for a heart to beat
Where it’s used:
Used
Widespread English
Examples
I'll be there in a heartbeat if you need me.
AI-drafted example auto-approved by rule (illustrative, not a corpus attestation)
Sources & notes
Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.
Common questions
What does “in a heartbeat” mean?
very quickly or immediately Literally: in the time it takes for a heart to beat
Is “in a heartbeat” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.