definitely

definitely — adverb

1. used to say that something is completely certain and there is no room for doubt

1.adverbA2
Definition

used to say that something is completely certain and there is no room for doubt or disagreement

Example

Rania definitely wants to join the art club this semester.

definitely + verb: emphatic certainty

That horror film was definitely the scariest one I have ever seen.

definitely + adjective complement (superlative)

Common collocations
  • definitely + want
  • definitely + need
  • definitely + worth
  • definitely + will
  • definitely + not
  • definitely + the best/worst/scariest
Synonyms
  • certainly

    similar strength but slightly more formal; common in written responses

  • absolutely

    even stronger; often used for emotional emphasis

  • undoubtedly

    more formal and less common in everyday speech

  • surely

    softer — implies strong belief rather than absolute certainty

Antonyms
  • possibly

    admits uncertainty and alternative outcomes

  • maybe

    informal; expresses only a chance rather than certainty

  • doubtfully

    directly opposes the idea of sureness

Grammar Patterns

definitely + verb

definitely + adjective

definitely + not

Usage Note

Frequently used as a one-word affirmative reply in spoken English, carrying stronger conviction than a plain 'yes'. Can combine with 'not' for a forceful negative. Unlike 'surely' or 'probably', this word expresses absolute certainty with no qualification.

Common Mistakes

She defiantly wants to come to the party.
She definitely wants to come to the party.
'defiantly' means 'in a rebellious way,' not 'certainly.'
I am definitely not sure about the answer.
I am definitely sure about the answer.
'definitely' and 'not sure' contradict each other; use 'not sure' on its own or replace with 'completely'.

Word family

Synonym discussion

Sense: adverb/1

All four words overlap with 'definitely' in expressing certainty, but they differ in force and context. 'Definitely' sits in the middle — strong enough for emphatic speech yet natural in everyday conversation. 'Certainly' is slightly more formal and is common in polite replies ('Certainly, sir'). 'Absolutely' is the most intense and emotional, often used in enthusiastic agreement. 'Undoubtedly' is more intellectual and formal, suited to written argument or analysis. 'Surely' expresses strong belief but allows a sliver of doubt — a speaker using 'surely' often expects confirmation. For example: 'I will definitely be there' (firm promise); 'The film is absolutely brilliant' (enthusiastic reaction); 'She is undoubtedly the best candidate' (analytical claim); 'Surely you remember me?' (expecting confirmation).

certainly ↗absolutely ↗undoubtedly ↗surely ↗

Common collocations

Phrases

  • definitely + verb
  • definitely + adjective
  • definitely + not
  • will definitely + verb

Etymology

LatinFrenchEnglish

Comes from the Latin word 'definitus', meaning 'limited' or 'defined', which developed through French into English as 'definite'. The '-ly' suffix turns the adjective into an adverb, giving the modern sense of 'in a fixed, certain way'. Over time, the meaning shifted from 'in a clearly defined manner' to 'without any doubt at all'.