inactivated

inactivated — verb

  • inactivatedpresent simple I / you / we / they
  • inactivateds3rd person singular
  • inactivateding-ing form
  • inactivatededpast simple

1. to stop a device, system, or mechanism from working or operating, usually by tur

1.verbtransitiveB2
Definition

to stop a device, system, or mechanism from working or operating, usually by turning it off or disconnecting it.

Example

The technician inactivated the fire alarm before welding in the hallway.

transitive: inactivate + [device/system]

After the security breach, the building manager inactivated all former employee key cards.

Common collocations
  • inactivate a system
  • inactivate a device
  • inactivate a function
  • inactivate an alarm
Synonyms
  • deactivate

    more common for digital accounts, cards, and software; suggests undoing a prior activation

  • disable

    implies making a function unavailable, often by cutting a connection; more informal

  • shut down

    informal phrasal verb for turning off completely

Antonyms
  • activate

    opposite action — to start or turn on

  • enable

    to make a function available again

Grammar Patterns

inactivate + [device/system/mechanism]

be inactivated (by [agent])

Usage Note

Object is usually a machine, security feature, or electronic function. Not used for people — use 'deactivate' for user accounts or 'turn off' for personal devices.

Common Mistakes

I inactivated my phone.
I turned off my phone.
'inactivate' sounds overly technical for everyday personal electronics.

2. to destroy or stop the biological activity of a substance such as an enzyme, pro

2.verbtransitiveC1
Definition

to destroy or stop the biological activity of a substance such as an enzyme, protein, or gene, so that it can no longer perform its natural function.

Example

Boiling the sample for five minutes inactivates the enzymes in the solution.

inactivate + [enzyme] as target of heat

The protein's function was inactivated when the chemical was added to the dish.

Common collocations
  • inactivate an enzyme
  • inactivate a protein
  • inactivate a gene
  • inactivate a growth signal
Synonyms
  • denature

    specifically describes changing a protein's structure so it no longer works; more technical

  • degrade

    implies breaking down into smaller parts; not always reversible

Antonyms
  • activate

    opposite — to start or enable a biological function

Grammar Patterns

inactivate + [enzyme/protein/gene]

inactivate + [biological process]

Usage Note

Frequently appears in passive voice in scientific writing ('was inactivated'). The agent is typically a treatment such as heat, a chemical, or a change in pH.

Common Mistakes

Heat inactivates the virus.' (when referring to vaccines).
Heat inactivates the enzyme.
'inactivate' for general biological functions vs. 'inactivate a pathogen' for disease-producing agents; use sense 3 for infectious agents.

3. to treat an infectious agent such as a virus or bacterium so that it can no long

3.verbtransitiveC1
Definition

to treat an infectious agent such as a virus or bacterium so that it can no longer cause disease, while often keeping its structure intact for use in medical research or vaccines.

Example

The viruses in this vaccine have been inactivated with formaldehyde to make them safe.

passive: inactivated virus / inactivated vaccine

Researchers inactivated the coronavirus so the immune system could learn to recognise it safely.

Common collocations
  • inactivated vaccine
  • inactivated virus
  • inactivated bacteria
  • inactivated pathogen
Synonyms
  • kill

    more direct and informal; commonly used for pathogens in everyday language

  • sterilise

    implies destroying all living organisms, not just disease-producing ability

Antonyms
  • activate

    to make a pathogen active or able to cause disease

  • infect

    opposite outcome — to introduce a pathogen into a host

Grammar Patterns

inactivate + [virus/bacterium/pathogen]

inactivated + [vaccine/virus] (attributive)

Usage Note

Distinguish from sense 2: sense 3 specifically targets whole infectious agents so they cannot cause disease, whereas sense 2 targets biological molecules (enzymes, proteins) to stop their biochemical activity. Commonly appears attributively as 'inactivated vaccine' or 'inactivated virus.'

Common Mistakes

The doctor inactivated the bacteria.' (doctor as subject).
The lab inactivated the bacteria using heat.
'inactivate' in this sense is a laboratory or manufacturing process, not something an individual does.

Word family

Synonym discussion

Sense: verb/1

These words all mean to stop something from working, but they differ in context and formality. 'Deactivate' is the most common synonym for digital accounts, cards, and software — it suggests reversing a prior activation (e.g., 'deactivate a social media account'). 'Disable' implies making a function unavailable, often by cutting a connection or breaking a link (e.g., 'disable location tracking on the phone'). 'Shut off' and 'turn off' are informal phrasal verbs used for physical switches and devices (e.g., 'turn off the lights', 'shut off the water supply'). 'Inactivate' is more formal and technical than the others, used mainly in security, industrial, or scientific contexts — you inactivate a building's fire alarm, not your bedside lamp.

deactivate ↗disable ↗shut off ↗turn off ↗

Common collocations

Nouns

Adverbs

  • chemically inactivated
  • thermally inactivated
  • completely inactivated
  • permanently inactivated
  • rapidly inactivated

Phrases

  • inactivated polio vaccine
  • inactivated influenza vaccine
  • chemically inactivated virus

Prepositions

  • inactivated by [agent]
  • inactivated with [substance]
  • inactivated through [process]

Etymology

LatinEnglish

Formed from the prefix 'in-' (meaning 'not') attached to 'activate', which comes from Latin 'activus' ('active') plus the verb suffix '-ate'. The word 'inactivate' was coined in the early 20th century, first appearing in scientific writing about chemistry and biology. Its use grew significantly with the development of killed-virus vaccines in the mid-1900s, where 'inactivated vaccine' became a standard term.

First known use

1906

1906, in the meaning defined above