irresponsible

irresponsible — adjective

1. acting or behaving without thinking about the possible bad results that your act

1.adjectiveB1
Definition

acting or behaving without thinking about the possible bad results that your actions could bring, especially when someone else gets hurt or a situation gets worse.

Example

It was irresponsible of Kenji to leave the campfire burning while he went swimming.

pattern: it + be + irresponsible + of + person + to-infinitive

Selim's irresponsible decision to skip the safety check caused a serious problem later.

attributive: irresponsible + noun (decision)

Common collocations
  • irresponsible behaviour
  • irresponsible decision
  • irresponsible attitude
  • irresponsible spending
  • irresponsible promise
  • irresponsible act
Synonyms
  • reckless

    stronger, implies a conscious disregard for danger rather than just neglect of duty

  • careless

    broader and milder; covers mistakes and inattention without the same moral judgement

  • thoughtless

    focuses on the social dimension — failing to consider others' feelings

  • negligent

    more formal, often used in legal or professional settings

Antonyms

Grammar Patterns

it + be + irresponsible + of + person + to-infinitive

irresponsible + noun (attributive)

feel/consider + someone + irresponsible (predicative)

Usage Note

Commonly used in the pattern 'it is irresponsible (of someone) to do something.' The adjective can appear before a noun (an irresponsible choice) or after linking verbs like 'be,' 'feel,' or 'seem.'

Common Mistakes

It is irresponsible for him to drive without a license.
It is irresponsible of him to drive without a license.
the correct preposition after 'irresponsible' when naming the person is 'of', not 'for'.
He is irresponsible person.
He is an irresponsible person.
'irresponsible' is an adjective and still needs a determiner before the noun it modifies.

irresponsible — noun

Word family

Synonym discussion

Sense: adjective/1

Irresponsible suggests a failure to meet obligations or think through consequences, carrying a clear moral judgement — a person who abandons their duties or acts without foresight. Reckless is stronger, implying a conscious disregard for danger (e.g., reckless driving). Careless is broader and milder, covering accidents and inattention (a careless mistake) without the same moral weight. Thoughtless focuses on the social dimension: failing to consider others' feelings (a thoughtless remark). Negligent is more formal and often used in legal or professional settings, suggesting a failure to exercise proper care (negligent supervision). While an irresponsible person might also be called careless, irresponsible carries a sharper judgement of character — it questions the person's sense of duty, not just their attention.

irresponsible ↗recklesscareless ↗thoughtlessnegligent

Common collocations

Adverbs

Phrases

  • it is irresponsible to

Prepositions

Etymology

LatinFrenchEnglish

From Latin 'ir-' (meaning 'not') + 'responsus' (past participle of 'respondere' — to answer, to respond). The word's earliest sense in English, dating from the mid-1700s, described someone who could not be held legally or morally answerable. By the 1800s the meaning broadened to its modern use: acting without concern for consequences. The noun form, meaning an irresponsible person, emerged in the 20th century.