unnatural
gb/ʌnnˈæt͡ʃɚəl/ us/ʌnnˈæt͡ʃɚəl/
B1
English
~ 5500
Senses
0 senses
adjective
B1
property
1
artificial; not from nature
Made or caused by people, not by nature.
Usage pattern:
an unnatural [substance/thing/process]
Common mistake:
Learners sometimes use "unnatural" instead of "artificial" for things like "unnatural intelligence" when the standard phrase is "artificial intelligence." Use "unnatural" more for describing how something contrasts with nature or looks/feels wrong, and "artificial" for most technical or product-related uses.
Synonyms
artificial (Very close in meaning; the most common everyday alternative when talking about things that are man-made rather than natural.)
|
synthetic (Often used in technical or scientific contexts, especially for materials like fabrics, drugs, or chemicals.)
Antonyms
natural (Describes something that exists or happens in nature without human action.)
Collocations
unnatural chemicals
|unnatural ingredients
|unnatural lighting
|unnatural color
|unnatural sweeteners
Themes
science
|environment
|technology
|core_vocabulary
Examples
- Some people try to avoid drinks with unnatural additives.
- The room was lit by a harsh, unnatural blue light.
- Scientists are concerned about the effects of these unnatural chemicals on wildlife.
- Her hair had an almost neon, completely unnatural shade of red.
Learner examples
- He does not like food with unnatural colors.
- The doctor warned him about the risks of using unnatural drugs.
- The photo has a strange, unnatural light.
- These flowers look beautiful, but their blue color is unnatural.
adjective
B2
property
2
strange; not normal or expected
Strange for that situation; it does not feel normal or right.
Usage pattern:
it is unnatural to [verb]
Common mistake:
Learners sometimes say "very unnatural" when they just mean "unusual" or "a bit strange." "Unnatural" often suggests that something feels strongly wrong or disturbing, not just different.
Synonyms
abnormal (More formal and often used in medical, psychological, or technical contexts; can sound stronger than "unnatural.")
|
odd (More informal and general; focuses on something being strange but not necessarily wrong.)
Antonyms
normal (Emphasizes that something is usual or standard for that situation.)
|
natural (Focuses on something fitting easily or comfortably with what people expect or feel is right.)
Collocations
unnatural silence
|unnatural calm
|unnatural position
|feel unnatural
|seem unnatural
Themes
emotions
|social
|psychology
|core_vocabulary
Examples
- There was an unnatural silence in the room after his remark.
- It felt unnatural to call my teacher by her first name.
- The city looked strangely empty, giving the streets an unnatural calm.
- Bending his arm that way would put it in a very unnatural position.
Learner examples
- For me, it is unnatural to speak English at home.
- There was an unnatural quiet in the house.
- Her smile looked unnatural and made me worry.
- The room was empty, and the silence was unnatural.
adjective
B2
property
3
forced or stiff in manner
Looking or sounding stiff, fake, or not relaxed, especially when a person talks, smiles, or moves.
Usage pattern:
an unnatural [smile/voice/laugh]
Common mistake:
Learners may confuse "unnatural" with "fake." "Fake" usually means something is not real at all, while "unnatural" often means it is real but looks or feels stiff, strange, or not easy.
Synonyms
forced (Stresses that the action is done without real feeling or ease.)
|
stilted (More formal; often used for speech or writing that sounds stiff and unnatural.)
Antonyms
natural (Shows that behavior or expression seems easy, relaxed, and genuine.)
|
relaxed (Focuses on being comfortable and free, without stiffness.)
Collocations
unnatural smile
|unnatural laugh
|unnatural voice
|unnatural pose
|unnatural body language
Themes
emotions
|communication
Examples
- She gave an unnatural smile when the camera turned toward her.
- His laugh sounded high and unnatural, as if he were trying too hard.
- The actor’s movements were stiff and unnatural in the first scene.
- The interview felt formal and unnatural, so it was hard to be myself.
Learner examples
- Her smile was big but unnatural.
- His voice sounded unnatural on the phone.
- He stood in an unnatural pose for the photo.
- Their conversation was slow and unnatural.
adjective
formal
C1
property
4
morally wrong; against nature
Seen as very wrong or shocking because it goes strongly against what people think is natural or morally right.
Usage pattern:
an unnatural [relationship/act/parent]
Common mistake:
Learners sometimes use this strong, moral sense when they only mean something is "unusual" or "strange." In everyday speech, use "strange" or "weird" for mild disapproval, and keep this sense of "unnatural" for serious moral or legal judgment.
Synonyms
perverse (Formal and strong; suggests a deliberate choice of what is morally wrong or twisted.)
|
deviant (Formal; stresses behavior that is very different from accepted social or sexual norms.)
Antonyms
wholesome (Emphasizes moral health and goodness, often in family or sexual behavior.)
|
proper (Stresses behavior that follows accepted social and moral rules.)
Collocations
unnatural acts
|unnatural relationship
|unnatural mother
|unnatural crime
|unnatural vice
Themes
law
|society
|morality
|relationships
|religion
Examples
- The judge described the abuse as an "unnatural crime" against a child.
- The novel explores an intense, almost unnatural relationship between the two brothers.
- Critics at the time called their love affair unnatural and immoral.
- She is accused in the press of being an unnatural mother for abandoning her children.
Learner examples
- In some laws, certain sexual acts were called unnatural acts.
- The newspaper wrote about an "unnatural crime" that shocked the town.
- People once said that their relationship was unnatural.
- He was judged for what others saw as unnatural behavior toward his family.
Grammar
Dictionary form
unnatural
IPA
GB/ʌnnˈæt͡ʃɚəl/
US/ʌnnˈæt͡ʃɚəl/
Syllables & stress
un - nat - ur - al (4 syllables)
Stress on 2nd syllable (nat)
Word forms
Adjective
- Base: unnatural
Word family
Negative and opposite forms
unnaturally
adverb
Related words
naturalist
noun
supernatural
adjective B2
Advanced or less common
naturalize
verb
naturalization
noun B2
Expressions
an unnatural calm
1/ən ʌnnˈæt͡ʃɚəl kˈɑm/
fixed phrase
strange calm when trouble looms
A calm feeling or situation that seems strange because people expect fear, noise, or trouble instead.
Examples
- There was an unnatural calm in the city on the morning of the strike.
- She spoke with an unnatural calm, even though she was clearly angry.
an unnatural silence
1/ən ʌnnˈæt͡ʃɚəl sˈaɪləns/
fixed phrase
strangely tense silence
A silence that feels strange or tense because people expect noise or talking at that time.
Examples
- An unnatural silence fell over the room when he announced the news.
- There was an unnatural silence in the streets after the storm passed.
unnatural act
1/ʌnnˈæt͡ʃɚəl ˈækt/
fixed phrase
formal
morally shocking or illegal act
A formal and often legal term for a sexual or violent act that people see as very wrong and against nature.
Examples
- The law once used the phrase "unnatural act" to punish certain private behaviors.
- He was charged with committing an unnatural act against a minor.
unnatural death
1/ʌnnˈæt͡ʃɚəl dˈɛθ/
fixed phrase
formal
death from non-natural causes
When someone dies because of an accident, violence, poisoning, or similar cause, not from illness or old age.
Examples
- The coroner ruled that it was an unnatural death and opened a full investigation.
- Insurance companies often look closely at any claim that involves an unnatural death.
unnatural mother
1/ʌnnˈæt͡ʃɚəl mˈʌðɚ/
fixed phrase
formal
mother seen as lacking care
A critical way to describe a mother who is seen as not loving or caring for her child in the usual way.
Examples
- The media painted her as an unnatural mother after the scandal.
- He accused her of being an unnatural mother for leaving her children alone.
unnatural relationship
1/ʌnnˈæt͡ʃɚəl ɹilˈeɪʃənʃˌɪp/
fixed phrase
formal
relationship seen as against norms
A relationship, often romantic or sexual, that some people see as very wrong or against nature and social rules.
Examples
- The tabloid described their affair as an "unnatural relationship."
- Old laws sometimes used the term "unnatural relationship" for couples that society did not accept.