# kill off

CEFR B1 · Phrasal verb

Source: https://englishreference.com/word/kill-off
Updated: 2026-04-24

## Definition

to eliminate or destroy something completely — often used for ending a competition, a story element, or a biological entity.

For teachers: to cause the complete destruction or elimination of something; often used in contexts of ending a competition, a story element, or a biological entity. The phrasal verb is separable in certain syntactic constructions but typically used as an inseparable unit.

## Examples

- The new policy will kill off the old system.
- The author decided to kill off the main character in the second chapter.
- The virus was designed to kill off all infected cells in the body.

## Pitfalls

- Not "The company decided to kill of the outdated product line." but "The company decided to kill off the outdated product line." — the particle 'off' is required; 'kill of' is not a valid construction.

## Usage notes

- typically followed by a noun indicating what is being destroyed or eliminated.
- Teaching tip: contrast with 'kill' (more general) and 'eliminate' (more formal); 'kill off' implies total eradication rather than mere harm.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.