English dictionary, thesaurus, translations & etymology
FreeDict.com
noun

EMP

ee-em-PEE

EMP (noun) means Electromagnetic pulse: a short, intense burst of electromagnetic energy that can induce damaging surges of current in electronics and power lines, produced by a nuclear detonation, a specialised weapon or a severe solar storm. Example: “A high-altitude EMP could knock out the grid across several states.”

noun
1
Electromagnetic pulse: a short, intense burst of electromagnetic energy that can induce damaging surges of current in electronics and power lines, produced by a nuclear detonation, a specialised weapon or a severe solar storm.
"A high-altitude EMP could knock out the grid across several states."
"The equipment is shielded to survive an EMP."
2
business, jargon Employee, used as an abbreviation in payroll systems, database fields and staff records.
"Enter the EMP ID before submitting the timesheet."

How to Use EMP

Learner’s notes

In plain EnglishA burst of energy that can fry electronics and knock out the power grid.

Easily confused with
EMF electromagnetic radiation geomagnetic storm HEMP
Common pairings
EMP attack high-altitude EMP EMP-hardened EMP protection
Study it as flashcards or scroll it in Flow — saved to your collection.
Test yourself on “EMP” A quick quiz — meaning, synonyms & usage

Fill the Gap

Can you complete this real example?

A high-altitude _____ could knock out the grid across several states.

Etymology

An initialism of 'electromagnetic pulse'.

Origin: English

electromagnetic pulse transient electromagnetic disturbance

Rhymes for EMP

See all rhymes for EMP →

Frequently Asked Questions

Would an EMP destroy phones and cars?

It depends on the strength and distance. A powerful high-altitude nuclear EMP could damage unshielded electronics over a wide area and would be most destructive to long conductors like power lines and telephone cable; testing suggests many modern cars would stall but a fair proportion would restart. Small devices that are switched off and unconnected are less vulnerable.

Does a Faraday cage protect against an EMP?

Yes, in principle. A sealed conductive enclosure shields whatever is inside from the incoming field, which is why a metal bin with a tight lid and insulated contents is a common improvised solution. The protection fails if any cable runs through the wall of the enclosure.

What is the difference between an EMP and a solar flare?

A nuclear EMP delivers an extremely fast pulse that damages small electronics directly. A geomagnetic storm caused by solar activity builds much more slowly and mainly induces currents in very long conductors, threatening transformers and the power grid rather than your laptop.

Featured In

Definitions: FreeDict original editorial · etymology from FreeDict original editorial