intelligent

intelligent — adjective

1. having or showing the natural ability to learn, understand, and think clearly an

1.adjectiveA2
Definition

having or showing the natural ability to learn, understand, and think clearly and quickly

Example

Nicholas is the most intelligent student in his physics class this semester.

collocation: intelligent + student (person)

The dolphins at the aquarium showed intelligent behaviour during the training session.

collocation: intelligent + behaviour (animals)

Common collocations
  • intelligent student
  • intelligent child
  • intelligent person
  • intelligent animal
  • intelligent being
  • intelligent behaviour
  • intelligent life
Synonyms
  • clever

    suggests quick-wittedness and problem-solving skill; slightly more informal than 'intelligent'

  • bright

    warmer, more informal tone; often used for children or students

  • smart

    most common informal alternative in American English; carries a practical, quick-learning nuance

  • brainy

    very informal; emphasises academic or intellectual ability with a positive, slightly playful tone

Antonyms
  • unintelligent

    direct opposite; more formal and less common than 'stupid'

  • stupid

    stronger and more negative; not a precise opposite in style

  • dull

    old-fashioned; suggests slowness in understanding

Grammar Patterns

adjective + noun (an intelligent student)

be + adjective (she is intelligent)

adverb + adjective (very intelligent)

Usage Note

Gradable: you can say 'more intelligent' or 'the most intelligent'. Typically describes people or animals. For objects or systems, it sometimes appears in technical or marketing contexts (e.g., 'intelligent device').

Common Mistakes

She is an intelligent woman with long hair.
She is an intelligent woman with a degree in engineering.
'Intelligent' describes mental ability, not physical appearance; pair it with details about someone's mind or achievements.
My dog is very intelligent, he can open the cupboard.
My dog is very smart, he can open the cupboard.
'Intelligent' sounds formal for animals; 'smart' or 'clever' is more natural in everyday speech about pets.

2. done with or showing careful thought and good judgment

2.adjectiveB2
Definition

done with or showing careful thought and good judgment

Example

Joaquín's intelligent analysis of the market helped the company avoid a serious loss.

collocation: intelligent + analysis / decision

The judge asked several intelligent questions during the court hearing this morning.

Common collocations
  • intelligent decision
  • intelligent choice
  • intelligent analysis
  • intelligent solution
  • intelligent question
  • intelligent approach
  • intelligent response
  • intelligent design
Synonyms
  • astute

    suggests sharp, practical judgment, especially in business or politics; more formal

  • perceptive

    emphasises the ability to notice and understand things others miss

  • insightful

    focuses on deep understanding that leads to a valuable observation

  • shrewd

    practical and clever, sometimes with a slightly self-interested tone

Antonyms
  • foolish

    describes decisions or actions that lack good judgment

  • unwise

    more formal; describes choices that are not sensible

Grammar Patterns

adjective + noun (an intelligent decision)

be + adjective (her analysis was intelligent)

Usage Note

Unlike Sense 1, which describes a person's general mental ability, this sense describes the result of thinking — a decision, analysis, question, or choice. The thing itself shows careful thought rather than the person being generally smart.

Common Mistakes

She is an intelligent judge, so everyone respects her.
The judge's intelligent ruling earned everyone's respect.
For sense 2, describe the outcome (ruling/decision), not the person in general. Use sense 1 for describing a person's overall ability.
He made an intelligent guess without any information.
He made an intelligent guess based on the available data.
This sense implies thought and reasoning; if no information or logic was used, 'lucky' or 'wild' is more appropriate.

Word family

Synonym discussion

Sense: adjective/1

Intelligent, smart, clever, bright, and brainy all describe someone with good mental ability. 'Intelligent' is the most neutral and formal — suitable for both written and spoken contexts. 'Smart' is more informal and very common in American English for everyday conversation ('a smart kid'). 'Clever' adds a nuance of quick-wittedness and sometimes slight trickiness ('a clever solution to the puzzle'). 'Bright' is friendly and encouraging, often used to describe children or learners ('a bright young student'). 'Brainy' is very informal and slightly old-fashioned, suggesting academic strength ('the brainy one in the family'). Use 'intelligent' in formal writing or when you want a precise, neutral tone; choose 'smart' or 'bright' for casual conversation.

smart ↗clever ↗bright ↗brainy

Common collocations

Nouns

  • intelligent person
  • intelligent being

Adverbs

  • highly intelligent
  • extremely intelligent
  • remarkably intelligent
  • very intelligent
  • quite intelligent

Phrases

  • artificial intelligence

Etymology

LatinFrenchEnglish

From Latin 'intelligēns' ('understanding, perceiving'), the present participle of 'intelligere' ('to understand'), which combines 'inter-' ('between') and 'legere' ('to choose, pick out, read'). The core idea is 'to choose between' — to discriminate and make sense of things. The word entered English through French in the late 1500s, originally carrying the sense of 'able to understand'.