English Reference
Idiom idiom

penny in the fusebox


An improvised repair made with no regard for safety.

Meaning adapted from Wiktionary, available under CC BY-SA 4.0.


SIMPLE

He put a penny in the fusebox and nearly started a fire.

You are taking a huge risk by putting a penny in the fusebox.

CONTEXTUAL

Desperate to get the lights back on, she used a penny in the fusebox instead of calling an electrician.

Using a bent paperclip to bridge the broken circuit was a dangerous penny in the fusebox that eventually fried the entire motherboard.

COMPLEX

The inspector shuddered at the sight: some previous tenant, seeking a quick fix, had jammed a penny in the fusebox, creating a hazard that could have burned the building down.


Derived from the literal practice of inserting a copper coin into a fusebox to restore an electrical circuit when a proper replacement was unavailable. While the copper permitted the current to flow, it lacked the safety mechanism of a melting fuse, rendering the improvisation hazardous and widely disdained. The habit was considered a desperate makeshift, tolerable only under extreme pressures such as wartime necessity, though it remained a permanent risk to the building in question.


Related idioms8entries
  1. 01

    a pound to a penny

    Very likely; almost certainly.

  2. 02

    bad penny

    A person or thing which is unpleasant, disreputable, or otherwise unwanted, especially one which repeatedly appears at inopportune times.

  3. 03

    penny for your thoughts

    Used to inquire into the thoughts and feelings of another, especially when the person appears pensive or conflicted.

  4. 04

    penny pincher

    One who spends little money; one who is very frugal or cautious with money.

  5. 05

    penny wedding

    A wedding at which the guests contribute payments in order to fund the event and to benefit the newly-married couple.

  6. 06

    penny wise and pound foolish

    Prudent and thrifty with small amounts of money, but wasteful with large amounts.

  7. 07

    pretty penny

    Chiefly preceded by a: a considerable amount of money; a high income or price.

  8. 08

    ten a penny

    So common as to be practically or almost worthless.

Last updated August 10, 2026