contaminate

contaminate — verb

1. to add a harmful or unwanted substance to something such as water, soil, or food

1.verbtransitiveB2
Definition

to add a harmful or unwanted substance to something such as water, soil, or food, so that it becomes dirty, unhealthy, or no longer safe to use.

Example

The factory waste contaminated the river, killing thousands of fish.

collocation: contaminated + river / water / soil

Bao accidentally contaminated the laboratory samples by touching them with bare hands.

passive equivalent: contaminated by + agent

Common collocations
  • contaminate the water supply
  • contaminate food
  • contaminate soil
  • contaminate samples
  • contaminate a crime scene
  • be contaminated with bacteria
  • be contaminated by waste
Synonyms
  • pollute

    broader scope, typically describes large-scale environmental damage to air, water, or land

  • taint

    suggests a small amount of impurity that spoils the whole; common in food-safety contexts

  • infect

    specifically about disease-causing microorganisms; implies biological spread through a host

Antonyms
  • purify

    to remove harmful substances and restore cleanliness

  • cleanse

    thorough cleaning, sometimes with a spiritual or medical sense

Grammar Patterns

contaminate + noun phrase (the object that becomes impure)

be contaminated with/by + noun phrase (the harmful substance or source)

Usage Note

Frequently appears in the passive voice (be/get contaminated). Common with prepositions 'by' (identifying the source) and 'with' (specifying the harmful substance). Particularly frequent in environmental, medical, and food-safety reporting.

Common Mistakes

The water contaminated with chemicals.
The water was contaminated with chemicals.
'contaminate' is transitive; without an object, you must use the passive form.
The bacteria contaminated the meat.' (sounds like bacteria were trying to make meat impure)
The meat was contaminated by bacteria.
For microorganisms, use passive or specify that the bacteria are the contaminating agent.

2. to harm people's thoughts, beliefs, or attitudes by introducing false, harmful,

2.verbtransitiveC1
Definition

to harm people's thoughts, beliefs, or attitudes by introducing false, harmful, or dishonest information.

Example

The senator accused the news channel of contaminating public opinion with misleading reports.

collocation: contaminate + public opinion

Sade's research shows that unchecked online rumors can contaminate people's understanding of science.

Common collocations
  • contaminate public opinion
  • contaminate young minds
  • contaminate the political process
  • contaminate judgment
  • contaminate the debate
Synonyms
  • corrupt

    stronger moral judgment; implies a deliberate turning from good to bad

  • poison

    more vivid and emotional; often used metaphorically for relationships or the atmosphere in a group

  • taint

    suggests a slight but lingering negative influence; less intense than 'corrupt'

Antonyms
  • purify

    to remove bad influences and restore moral or intellectual clarity

Grammar Patterns

contaminate + abstract noun (mind / opinion / values / judgment)

contaminate + noun phrase + with + noun phrase (the bad influence)

Usage Note

Almost exclusively formal or literary; rarely heard in casual conversation. Common abstract objects include 'mind(s)', 'opinion', 'values', 'attitudes', 'judgment', and 'the political process'. Avoid using a person as the direct object — the target must be an abstract quality or a group of people referred to by a collective noun.

Common Mistakes

The violent movie contaminated my little brother.
My parents worried that violent media could contaminate young children's values.
The direct object should be an abstract concept (mind/values/beliefs), not a person.

Word family

  • contamination
    nounB2
  • contaminant
    nounB2
  • contaminated
    adjectiveB2
  • contaminator
    nounC1
  • decontaminate
    verbC1
  • decontamination
    nounC1

Synonym discussion

Sense: verb/1

All three words describe making something impure, but they differ in scope and typical contexts. Contaminate focuses on the introduction of a harmful or unwanted element — it is the most neutral and technical of the three, common in scientific and formal writing ('contaminated water supply'). Pollute is broader and carries stronger environmental and moral overtones; it typically describes large-scale damage to natural resources ('pollute the air') and often implies a legal or ethical violation. Taint suggests a smaller amount of impurity that nevertheless spoils the whole — a batch of food can be tainted by a single spoiled ingredient. In everyday usage, contaminate is the most precise for describing physical or chemical impurity, while pollute is more general and taint more particular about the effect of a small bad element on the whole.

contaminate ↗pollute ↗taint

Common collocations

Nouns

Adverbs

Phrases

  • contaminate the water supply
  • contaminate the evidence
  • contaminate a crime scene

Prepositions

Etymology

LatinFrenchEnglish

From Latin contaminatus, past participle of contaminare ('to make impure, to defile'), related to contamen ('contact, pollution'), which itself comes from tangere ('to touch'). The physical sense of making something impure entered English in the 15th century; the figurative meaning of corrupting ideas or morals developed in the 17th century.