penny in the fusebox
Proposed by a contributor, not yet supported by evidence.
Meaning · English
a small problem that causes much larger issues
Literally: a coin inserted into an electrical fusebox
Where it’s used:
Used
Widespread English
Examples
The penny in the fusebox was what led to the entire system shutting down.
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 “penny in the fusebox” mean?
a small problem that causes much larger issues Literally: a coin inserted into an electrical fusebox
Is “penny in the fusebox” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.