conscious

conscious — adjective

1. knowing that something — a person, an object, or an event — is present or taking

1.adjectiveB1
Definition

knowing that something — a person, an object, or an event — is present or taking place near you

Example

Linh was conscious of the tension in the room as soon as she walked in.

conscious of [something]

Jabari suddenly became conscious of the fact that everyone was staring at him.

become conscious of the fact that…

Common collocations
  • conscious of the fact
  • conscious of the need
  • acutely conscious of
  • painfully conscious of
  • fully conscious of
Synonyms
  • aware

    more neutral and slightly more common; 'aware of' can apply to physical and abstract things equally

  • mindful

    implies careful attention and deliberate thought, not just passive noticing

  • cognizant

    formal register; typically used in legal or official contexts

Antonyms
  • unaware

    the direct opposite in everyday use

  • oblivious

    stronger — suggests a complete failure to notice something obvious

Usage Note

Frequently used in the pattern 'conscious of + noun/gerund' or 'conscious that + clause'. Less common in affirmative simple-present than in negative or question forms.

Common Mistakes

He was conscious the problem.
He was conscious of the problem.
'conscious' requires the preposition 'of' before its object.
She was conscious to the noise outside.
She was conscious of the noise outside.
'conscious of' is the only correct preposition pattern for this sense.

2. in a condition in which you are not asleep, your mind is working, and you can se

2.adjectiveB1
Definition

in a condition in which you are not asleep, your mind is working, and you can sense the things near you

Example

Yuki remained conscious throughout the entire medical examination.

remain conscious

The patient was barely conscious when the ambulance arrived at the hospital.

barely conscious

Common collocations
  • conscious and alert
  • conscious but disoriented
  • fully conscious
  • barely conscious
  • still conscious
Synonyms
  • awake

    everyday word for not sleeping; 'conscious' adds the idea of mental awareness, not just open eyes

  • alert

    implies the ability to respond quickly, not just basic awareness

  • lucid

    implies clear thinking; often used after illness or confusion

Antonyms

Usage Note

Common in medical contexts. Frequently paired with adverbs of degree: 'fully', 'barely', 'partially', 'semi-'. The opposite is 'unconscious', not 'asleep'.

Common Mistakes

The doctor said he was conscious asleep.
The doctor said he was unconscious.
'conscious' and 'asleep' are not opposites; the opposite of 'conscious' is 'unconscious'.

3. done on purpose because you have thought about it and made a clear decision, not

3.adjectiveB2
Definition

done on purpose because you have thought about it and made a clear decision, not by accident

Example

Constanza made a conscious effort to arrive early for every team meeting.

make a conscious effort to [do]

Lucas's decision to leave his job was a conscious choice after months of careful thought.

a conscious choice

Common collocations
  • conscious effort
  • conscious decision
  • conscious choice
  • conscious attempt
Synonyms
  • deliberate

    closest synonym; can also describe negative actions, which 'conscious' typically avoids

  • intentional

    very similar; often used in legal or moral contexts

  • purposeful

    suggests determination and a clear goal

  • voluntary

    focuses on the freedom of choice rather than the thought process

Antonyms

Usage Note

The noun phrase patterns 'a conscious effort / choice / decision / attempt' are very common. The pattern implies the action required thought and was not habitual or instinctive.

Common Mistakes

He made a conscious decision by accident.' — contradictory.
He made a conscious decision to change his habits.
'conscious' here means deliberate, not accidental.

4. giving a lot of attention to a particular issue because you care about it or bel

4.adjectiveB2
Definition

giving a lot of attention to a particular issue because you care about it or believe it matters a great deal

Example

The company is becoming more environmentally conscious about its packaging materials.

environmentally conscious

Maja is very health-conscious and checks the sugar content of everything she eats.

health-conscious

Common collocations
  • health-conscious
  • environmentally conscious
  • safety-conscious
  • budget-conscious
  • fashion-conscious
  • cost-conscious
  • eco-conscious
Synonyms
  • concerned

    similar meaning but used as a standalone adjective with 'about'; less compact than the compound pattern

  • aware

    weaker than 'conscious' — can mean just noticing without caring

Antonyms

Usage Note

This sense is most often used as the second part of a compound adjective: 'health-conscious', 'environmentally conscious', 'safety-conscious', 'budget-conscious', 'fashion-conscious'. The first element names the issue someone cares about.

Common Mistakes

She is conscious about environmental problems.' (intending sense 4)
She is environmentally conscious.
The compound adjective pattern is the standard way to express this meaning.
He is conscious of his health.' (this is sense 1 — just awareness)
He is health-conscious.' (this is sense 4
active concern and behaviour)

conscious — noun

conscious — suffix

Word family

Synonym discussion

Sense: adjective/1

All four words describe knowing about something, but they differ in strength and focus. AWARE is the most neutral and common — it simply means you have information about something ('She was aware of the meeting time'). MINDFUL goes a step further: it suggests you are paying careful attention and keeping something in your thoughts deliberately ('He was mindful of his tone when speaking to upset customers'). COGNIZANT is formal and often appears in legal or official writing ('The company is cognizant of its obligations under the contract'). ALERT implies readiness to respond, not just passive knowledge ('Security guards must stay alert to unusual behaviour'). For everyday use, 'aware' is safest; 'conscious of' sits between 'aware' and 'mindful', carrying a slightly stronger sense of active noticing.

aware ↗mindfulcognizantalert ↗

Common collocations

Nouns

Adverbs

Phrases

  • conscious of the fact that
  • conscious of the need to
  • make a conscious effort

Prepositions

Etymology

LatinFrenchEnglish

'Conscious' entered English in the 16th century from French 'conscient', which came from Latin 'conscius' — a combination of 'com-' (together) and 'scire' (to know). Literally, it meant 'knowing together with' or 'sharing knowledge', originally referring to shared awareness between people. By the 17th century it had shifted inward to mean 'aware of one's own thoughts and feelings' — the sense closest to its modern use.