Dictionary.com
Thesaurus.com
Synonyms

witness

American  
[wit-nis] / ˈwɪt nɪs /

verb (used with object)

  1. to see, hear, or know by personal presence and perception.

    to witness an accident.

    Synonyms:
    note, notice, mark, watch, perceive
  2. to be present at (an occurrence) as a formal witness, spectator, bystander, etc..

    She witnessed our wedding.

  3. to bear witness to; testify to; give or afford evidence of.

  4. to attest by one's signature.

    He witnessed her will.


verb (used without object)

  1. to bear witness; testify; give or afford evidence.

noun

  1. an individual who, being present, personally sees or perceives a thing; a beholder, spectator, or eyewitness.

  2. a person or thing that affords evidence.

  3. a person who gives testimony, as in a court of law.

  4. a person who signs a document attesting the genuineness of its execution.

  5. testimony or evidence.

    to bear witness to her suffering.

    Synonyms:
    substantiation, confirmation, proof
  6. (initial capital letter) a member of the Jehovah's Witnesses.

witness British  
/ ˈwɪtnɪs /

noun

  1. a person who has seen or can give first-hand evidence of some event

  2. a person or thing giving or serving as evidence

  3. a person who testifies, esp in a court of law, to events or facts within his own knowledge

  4. a person who attests to the genuineness of a document, signature, etc, by adding his own signature

    1. to give written or oral testimony

    2. to be evidence or proof of

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (tr) to see, be present at, or know at first hand

  2. to give or serve as evidence (of)

  3. (tr) to be the scene or setting of

    this field has witnessed a battle

  4. (intr) to testify, esp in a court of law, to events within a person's own knowledge

  5. (tr) to attest to the genuineness of (a document, signature, etc) by adding one's own signature

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Usage

What does witness mean? A witness is someone who was present at or perceives an incident, event, or occurrence, as in Jamal was a witness to the fact that I completed all my homework. People who witness something typically do so through seeing, although they can also witness a smell or sound. In order to witness an event, one must simply be present at the time the event happened, even if the witness was not directly involved. To witness something is to see, hear, sense, or know something, as in I witnessed our dog running out the door, but I didn’t see where she went. To witness is also to testify or give evidence, especially in a court of law. Example: The key witness in the theft case was a local shop owner.

Related Words

See observe.

Other Word Forms

Etymology

Origin of witness

First recorded before 950; (noun) Middle English, Old English witnes originally, “knowledge, understanding”; see wit 1, -ness; (verb) Middle English, derivative of the noun

Explanation

If you're walking down the street and see one car run a red light and plow into another, you are a witness to the accident. You saw it and can tell someone else how the accident happened. The first part of a witness's role is observation. You witness the accident. The second part is telling someone about it — bearing witness. In court, you can be a witness for the defense or prosecution. You can also witness a legal document, like a will, or a wedding conducted by the justice of the peace. Religious people use this word a lot too: being a witness in that sense is being a true believer who tries to convert others.

Keep Reading on Vocabulary.com

Vocabulary lists containing witness

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Witness the Pentagon’s urgency to relocate Awacs-like functions from manned aircraft to orbiting platforms.

From The Wall Street Journal • Apr. 24, 2026

Witness testimony, medical history and the timing of any changes made to estates can help establish a case for undue influence.

From MarketWatch • Mar. 30, 2026

"They have a narrative that they're pushing," says Mahsa Alimardani, from the human rights organisation Witness.

From BBC • Mar. 15, 2026

Many with ties to Iran are still receiving landline phone calls from inside -- "quite surprising" given the internet blackout, said Mahsa Alimardani of global rights organisation Witness.

From Barron's • Mar. 13, 2026

A major figure despite his obscurity, Sky Witness set out to destroy Mutal.

From "1491" by Charles C. Mann